Minecraft 1.6.4 and RC 8.1.0.0 (Forge 884)
When placing a switch track, crashes. Crash log here : http://pastebin.com/93NWsZsQ (Two slightly different crash logs)
Seems to be when you have a lot of track around the switch track, rather than placing it on it's own or attached to one piece of track.

Hmm....that's the crash reporter crashing, stuff like that usually only happens during either stack overflows or out of memory situations where the classloader can't load any classes.

If I had to guess, I'd say you need to increase your permagen memory with the following JVM argument:

-XX:MaxPermSize=128m

128 to 256 mb is typically more than sufficient (the default is 64 mb). Anything larger is massive overkill.

Thanks, I'll do that. As a workaround, I spaced the tracks out a bit.