"Form New Sub-assembly Here" crash in SW2008

I tried to use function "Form New Sub-assembly Here" a fewtimes in 2008. Have hard time to complete the task.
SW will crash as I drag piping assemblies into new sub-assembly.Today I was forced to use backup files. Because new files will notopen. Will crash with message "An error has occurred and SolidWorksneeds to restart".
Piping routes become corrupted. Will crash as well. Had to recreatethem.

Anyone had experienced this or it's just me?

thanks,SolidworksAssemblies