Ok this is happened to me twice now and I cannot figure out why.
I have everything updated
Windows7 64bit
ATI 5870 x2
Java updated
I have 2 gigs allocated to Tekkit and its not maxing out
But when I join my server I get 2 seconds of movement then my graphics drivers crash. There are no new machine blocks in the area only reinforced stone/glass and glowstone. If I am on the server and near where they are placed it works. However if I try to log back in it crashes. The only way I have found to fix this is restart my char data so I start at spawn. If I use world edit to regen the entire area I can go there without crashing.
A fix to this would be really appreciated since it seems to be happening to many players.