TidBITs has a more in-depth report on the bug that causes the Snow Leopard Finder to report error-36 when copying files to shared drives. The article includes some Terminal instructions to work around the problem.
Quick Look killing the Finder?
The PowerBook was having some problems with the Finder continuously hanging under Mac OS X 10.5.2. After having been fast enough to open Terminal and Console between Finder hangs it appeared that the cause was Quick Look continually having problems generating thumbnails for some avi files (which the machine didn’t have a decoder plugin for), some gifs with a zero dimension (ie 9×0), and some other files.The solution (at least to the Finder falling over) seemed to be to open up the View Options from the View menu and turning off both the “Show Icon Preview” and “Show Preview Column” (these options are available when the Finder is using Column view for the frontmost window).