I am attempting to run LR on two separate PC's: work and home. I use MS Synctoy to syncronize the photo files and LR Catalog, BUT I have found LR crashes ("LR has encountered an error and must shut down") which I expect is due to the lack of syncronized Lightroom Catalog Previews. Is it really necessary to copy these hundreds of little files back and forth between computers? I thought LR would just re-create these previews if they weren't present. I, of course, want to keep my editing steps intact on both computers or I could just use "export catalog". Any suggestions?