Hi there!
I had a server crash issue with one of my Funky Locomotion machines. It seemed to have corrupted a chunk as when the chunk was deleted and regenerated everything was fine.

http://pastebin.com/v9eBPg7e

I was using it with the Buildcraft mod, the Solar Expansion mod and the Thermal Expansion mod.

Were you trying to use the machine in an unloaded chunk?

It did have a chunkloader on it but it might have ran out so it probably unloaded. When the chunk it was in was loaded the whole server crashed...