Users of Adobe System's popular design software, including PhotoShop and InDesign, have reported that after updating their Macs to the latest version of Leopard, files get corrupted when saved to network servers.

Apple had no immediate explanation, but a spokesman pointed to a year-old Adobe warning of potential problems when saving files to network drives.

Apple released Mac OS X 10.5.3, an update that fixed more than 100 security vulnerabilities and other problems, on Wednesday.

By the next morning, users were complaining on both Adobe's and Apple's support forums that files created by its CS3 suite applications -- PhotoShop is the best known in the bundle -- were being corrupted.

"Essentially, PhotoShop doesn't recognize the files after saving edits on an existing X Server, thus ruining your file," said a user named Kevin Moran in a message posted to an Adobe support forum Thursday.

"I too got @#$%^&ed by this for every file I worked on today," added a user identified as "chazcron" on the same thread.

PhotoShop and InDesign users also reported the same problem on Apple's support forum, and stressed that the file corruption only started after they'd updated to Mac OS X 10.5 .3.

"Started right after installing the 10.5.3 update," claimed "Traumarama" in a post to the Leopard forum. "No one else can open my files either. I've tried the usual fixes. What to do now?"

"Since installing the update I have had the same problem with .psd and .tif files becoming corrupt," added Rik Tweed on the Apple thread. "I am likewise working with files on a shared volume, which I have done for years with no problem. I cannot get the corrupted files open locally or remotely and creating new copies does not help."

Adobe did not responded to questions about the extent of the problem, when it would be fixed and where the fault lay. Apple, meanwhile, had no answers to the same questions, but spokesman Anuj Nayar pointed out an Adobe support document from January 2007.

That document spells out problems with the then-current Mac OS X, dubbed Tiger. "Mac OS X 10.4.6 uses newer AppleShare components which conflict with PhotoShop when you save a file to a server," said the Adobe document, which also told users it does not support opening or saving files from a server "because of potential file corruption."

Adobe indicated then that the problem -- which popped up after users updated from 10.4.5 to 10.4.6 -- was Apple's fault.

Users, meanwhile, reported that although saving to a network drive corrupted their files, using the Save As command instead did not. "I think I found a way to work around it," said a user using the "backfliprabbit" alias. "If you do Save As and replace the old file with the same name, it will let you open."

Others had more advice along the Save As lines. "If a Save As avoids corruption, disable the Command-S for Save in the Keyboard Shortcuts and apply it to Save As," said Moran on the Apple forum.

According to users posting to that same Apple forum, the damaged files are missing most of the header data Adobe normally puts at the file's beginning.

Users saving Adobe CS3 files to both Mac- and Windows-based servers have reported corrupted files.