Users running Firefox along with popular Norton security programs have reported problems after updating the browser to version 3.0.1, according to messages on Symantec's and Mozilla's support forums.

Mozilla has confirmed the accounts.

"Some of the problems seem to be related to Identity Safe, which is a feature of Norton 360 and other Norton and Symantec offerings," said Mike Beltzner, Mozilla's director for Firefox. "[But] it's not clear that all of the problems are related to that single feature."

Beltzner was responding to questions about post-update problems mentioned during Mozilla's weekly Firefox status meeting on Wednesday, when the Norton 360 issue was brought up.

Messages posted by Symantec customers and Firefox users pointed to a wide range of problems with both Norton titles and Firefox, but a majority of the latter said their bookmarks had gone missing, as had the back and forward buttons, after they updated to 3.0.1. Mozilla started pitching that version to users of the older Firefox 2.0.0.16 last week when it turned on an automatic update offer.

Firefox users have been reporting the problem for months -- Firefox 3.0 launched in mid-June -- but the automatic update appeared to push the issue to the forefront.

Symantec customers, meanwhile, complained about the disappearance of Identity Safe, a password manager that's bundled with numerous Symantec security products, including Norton 360 2.0 and Norton Internet Security 2008, after upgrading Firefox.

"I just installed Firefox 3 under XP and have apparently lost Identity Safe which I depend on," said a user identified as "BobinVA" on a Symantec forum in a message posted last Sunday. "How can I get it back?"

Beltzner said Mozilla and Symantec are on the case. "We're working with people from Norton to try and understand the problems better," he said. "To date, though, neither we nor Norton have been unable to reproduce the problem in our QA labs."

According to Beltzner, older installations of Norton software, most likely those that haven't been kept up-to-date with downloads from Symantec, seem to prevent Firefox from terminating properly when the browser shuts down. "When the user starts up Firefox the next time, the file that's used to store their bookmarks and history can't be read, and as a result the back and forward buttons don't work and no bookmarks are shown," he said. "This coincides with the Identity Safe feature not working as well."

Some users had reported that a reboot ended their problems, Beltzner said. Others have used a Mozilla support document titled "Configuring Norton 360" to quash the issue. "We'll keep looking into the problem, and while it's not happening for all Norton and Firefox users, we understand that for the users it is affecting, it's a significant problem," Beltzner said.

For its part, Symantec urged users of Norton Internet Security 2008 to first update to version 15.5, which in turn would allow them to download and install a Firefox 3.0 compatibility update. A separate Firefox 3.0 compatibility patch is available for Norton 360. Both patches can be obtained by launching Symantec's Live Update feature from within the security applications.

This wouldn't be the first time that Symantec's Norton software has created problems for other vendors. In May, shortly after Microsoft launched Windows XP Service Pack 3 (SP3), users blamed the Symantec programs for crippling their PCs after they updated to SP3.

Initially, Symantec said the bug was Microsoft's fault, but it accepted some responsibility, saying the combination of a flawed Microsoft process and the SymProtect feature in its Norton software had added errant entries to XP's registry. Later Symantec released a free tool that cleaned up]] the corrupted registry keys.