Your files may be corrupted. Use a disk utility like Norton File Saver or Techtool Pro to check them. If you do not have either program, simply use ResEdit. Launch ResEdit and click "cancel" because you do not want to open a file, then go to the file menu and click on verify. A window will open for you to find the file you wish to verify, so find and select each file in your plug-ins folder one at a time.
I had a corrupted copy of Frozen Heart and found it with ResEdit using this method. If this method shows there is a problem, download a fresh version. If there is no problem in the plug-ins, perhaps the EVO files themselves have become corrupted. If so, check them using the verify method in ResEdit. Re-install any faulty files.
If all the plug-ins and EVO files are fine, perhaps your pilot file itself is corrupted. Trash it and create a new pilot.
By the way, you should have at least two extension configurations on your Mac: one for gaming and one or more for other tasks. I only play games on my Mac with the bare minimum extensions necessary to run games, then I allocate 5 MB less memory to each game than what is available in the "About this Macintosh" window. I have 384 megs of ram, so I have 335 megs available when running under the bare minimum gaming extensions configuration. Therefore, I allocate 330 megs of ram to EVO or any other game on my hard drive. Do I ever crash? Not while gaming.