Users of Adobeis Photoshop and inDesign are reporting that the Leopard 10.5.3 update causes their files to be corrupted when loaded from and then saved back to file servers. Backgrading to 10.5.2 eliminates the problem. Apple has pointed to an Adobe document that advises against saving directly to servers and recommends saving locally, then transferring to the server.
An Apple spokesperson, Anuj Nayar has pointed to an Adobe support document that advises against re-saving work directly to servers and offers some advice for handling files. "Adobe does not support opening from or saving a file to a server, because of potential file corruption," according to Adobe document #333037.
Various users have reported workarounds, but the consensus seems to be either to backgrade to 10.5.2, or likely better, always save locally, then use trusted techniques to back up the files to a network server.