Random End of Stream errors on SMP tekkit, not sure why.

[vxShadowflarexv]

There is like 4 players on my tekkit server, whenever all 4 are on at the same time, it randomly end of streams other players, sometimes even myself and others who are connecting locally..three people appears to be mostly stable. Does anyone have any ideas of why this happens? I've tried loading up a new world to see if the world was corrupt or something. Soon as we hit 4, it starts a carousel of end-of-stream disconnects. Thanks in advance.

EDIT: Sometimes it just happens when people connect, it'll boot off existing players..

Computer Specs: Win7 64 bit, 8 GB of ram, 3.4 Ghz quad core. The server client is using about 2 gigs of RAM on average, and the game client about 1.8

UPDATE: Been playing with it some more, found out I get the same error on vanilla, traced the cause back to java 1.7, when I use 1.6, as many people as I'd like can login and be stable, soon as I hit 1.7, end of stream errors galore.