any suggestions preventing crash to desktop?

I have an assembly made out of 40 or so parts (made in solidworks 2003 sp2. All I want to do is change a hole created with hole wizard, from being a straight through hole into a 100 degree c'sunk hole. I've tried 2 methods to accomplish this: I've tried editing the part while still in the assembly in witch it appears. I then right click on the hole that I wish to change and select edit definition. Doing so brings up the opportunity to change the hole spec, I switch it to countersink by selecting the tab, then solidworks looks like it's going to do what I ask, but instead, after about 15 seconds, or so, it crashes to desktop. The second method that I've tried was to do the same procedure as before, with the only difference being that instead of editing the part that contains the holes that I want to change, while still in the assembly, I open the part with the holes in its own window, close down the assembly that it appears in, then edit the hole's definition in the newly opened window, but the same ctd happens (clicking on any of the tabs in the edit definition dialog box makes sw2003 sp2 crash to desktop. Any suggestions, that help prevent me having to delete the whole pattern, would be appreciated.