Magister

a port does not generally need to be opened for an outgoing connection, and since the op said it worked days before and then stopped it is doutbfull that it is an issue with ports or router, even more since the op is able to connect to server from another computer on the same net the most possibly problem is something on the ops computer itself, either with the java installation, local windows firewall, or with the host file but since the op has tried to connect to other server and has had the same issue i doubt it would be the host file OP, clear out your logs for tekkit, try joining a server once then post the log, it might give more insight

delete the folder .techniclauncher in %appdata% and the start from the begining and redownload everything

on server or single player? and that is generally due to a slow loading time, you freefall while it is retrieving the map chunks

23:01:20 [WARNING] Failed to load mod class net/minecraft/server/mod_NetherOres.class ^shows that the mod in questions is netherores, dont know why advanced computer mod would fix anything and as for your problem with java System Requirements Any Intel-based Mac running Mac OS X 10.7.3 (Lion) or later. Administrator privileges. OS: Mac OS 10.6.8 ^from your OP

i have seen this before on my own server, it happened to be slow hd read times from what i could figure out, after ramdisking the worlds it ran much smoother

go into the configs and manually changes the ids

engines produce mj which are used for buildcraft machines (such as quarry), the macerator and extractor are ic2 machines and are powered by eu

fully remove and reinstall java and then try again

Java Version: 1.6.0_24 20:29:06 [sEVERE] Zip file mod_NetherOres.jar failed to read properly netherores requires java 1.7 in order to run, either disable it or update

64 bit java will simply allow for setting a higher amount of working memory for java, and as far as running it on windows or non windows i have tried both and have not seem much of a difference in performance, you also have to keep in mind that tekkit has alot more loaded than just normal minecraft the main problem is when the op is running tekkit it only is allocating 256mb which means the rest is allocated to other things and may not be a java problem but simple a system load problem. reducing the gpu load would help get higher fps but would not attribute to an out of memory error, but depending on what the op is using for a video card it could since system ram can be used for extra texture memory if the card does not have much of its own

on your start up script for the server add -nojline at the end of the java line

you need to close background programs (anything you do not want running or can live without while playing) before starting tekkit and give it a try, firefox is a big one if you use it, since its plugin container tends to swell with time and take alot of resources

what mods did you try to add in? if you added multiples you may want to remove them and then add them one at a time starting after each is added till you find which is causing the issue

java.lang.IllegalArgumentException: Slot 241 is already occupied by codechicken.enderstorage.BlockEnderChest@2203a0f2 when adding ic2.common.BlockRubSapling@1c3b8150 there is your problem, multiple items with the same id

have you checked to make sure you are using 64 bit java? it only allowing 1536mb sounds more like tekkit is using 32bit, also when the game is running f3 to see how much is actually being allocated to tekkit, the settings in the launcher is the maximum size that it will use, and if you have other things running in the background it can end up using far less intel integrated graphics have very few to no options that can generally be modified

make sure the engine is pointed at something that it can power, and i do not think a redstone engine will output to a conductive pipe as far as the wrench, make sure it is a buildcraft wrench you are trying to use

is the server on the same pc as the one you are trying to connect? if it is on the same pc then try connection use 127.0.0.1 instead since 25565 is the default port number for minecraft you do not have to specify it when connecting to a server unless that server uses a different port the connection being refused points towards a firewall

removed, didnt not realize the OP was from that far back until after i posted a reply to the reply

what video card you have in it? are your drivers up to date?

i think you may be missing the point of using hamachi for a server, typiclally you do not need to do as much port forwarding since it is a vpn, also portforwarding can be drastically different depending on what router you are using http://portforward.com/routers.htm has a walkthrough for most, just pick the router manufacturer model and even the program you are wanting to forward for and it will tell you, step by step

windows 7 has an icon for recieving a connection to a router or dhcp server, and another one for having an active internet connection easiest way to determine an unstable connection is to do a ping -t and watch the time, if it has large differences from one result to another or it gets unable to find host you have a problem also since other things work except this it could be as simple as a error in the host file or the dns cache on the router/modem

the OP has stated that he is used hamachi, a 5.0.0.0 address is generally always hamachi and as part of a vpn will not be adressable from an outside source, unless additional static routing has been placed to do so. when a program attempts to bind to a network adapter it will always try to bind to the one with the lowest metric hence my last post to the OP, another option is to use forcebindip instead of metric but adds extra lines to startup scripts generally when dealing with vpn connected clients are given a static ip or a dynamic ip with a very long duration

hamachi creates a virtual adapter used for vpn, in order for it to have an "outside" connection you will need to make static routes in the ip table in order to bridge the networks

for hamachi before you start the server you need to make sure that the server will bind to the hamachi adapter best way to do this is to adjust the metic setting on the hamachi adapter and your normal adapter Network Sharing Center > Adapter Settings > Right Click the adapter > Properties > selcet ip4 or ip6 depending on what you are using > Properties > Advanced at the bottom of the new window > unclick automatic metric > set hamachi to 1 your other adapter to 10 or higher disable the firewall on the hamachi adapter and give it a try

when checking a firewall it is best to just fully disable it and try a connection are you able to connect using vanilla minecraft or is the problem only with tekkit on that computer? it may be an issue with java somewhere, you can always try a full reinstall of it