My Launcher opens quickly then disapears

[AquaticWhale]

Launcher Version: unknown (downloaded 7-21-12)

Operating System: windows XP

Java Version: Java 5.0

Antivirus Program:

Description of Problem:

I have tried to download this mod pack many times but every time I try to open the launcher it would say checking launcher version. I have tried a lot of things. Please help.

Error Messages:

Error Log:

[The_DarthMoogle]

Update to the latest version of Java,

and use the .jar

[Torezu]

Java Version: Java 5.0

Ewwwww...

Also, do you have an antivirus program? You left it blank.

[AquaticWhale]

I tried to use the .Jar and it said unable to launch application. I also updated Java.