When I download an Office file and double click it from the Downloads window or from Finder, the associated program will open, but the file won't. It worked before I upgraded from Tiger to Snow Leopard. How do I fix this?
Did you update Office as well as Mac OS X ?
Some earlier version were not compatible with Snow Leopard (even if the last one isn't 100% reliable).
Latest version available is 11.5.7.
Make sure you also have Rosetta installed (it comes on Snow Leopard DVD).
But even with all this, Office 2004 code is PPC only and isn't supported anymore …