crashing

My final cut pro x keeps krashing like crazy?!!! I can't render the file, I can't edit because it keeps crashing. I don't know what to do? I have a mac pro 2.93 ghz quad core intel Xeon, 16 gig ddr3 ram. I put all the data onta an internal hard disk so I don't think its power? I am using a lot of filters effect etc, and it seems to be rendering these things and then it just crashes? Any help would be greatful!! Thanks!

cheers

Marc