I am unable to bookmark any sites or download any add ons. I get an error message. A Parson Error not well formed. it sais that

[Birgit]

Binary package hint: firefox-3.0

If I wanted to bookmark this particular page or any other I get the following message

XML Parsing Error; syntax error
Location: chrome://browser/content/bookmarks.addBookmark2.xul
LIne Number 1, Column 1:

ProblemType: Bug
Architecture: i386
Date: Fri Nov 14 17:01:38 2008
DistroRelease: Ubuntu 7.10
NonfreeKernelModules: nvidia
Package: firefox 2.0.0.17+1nobinonly-0ubuntu0.7.10
PackageArchitecture: all
SourcePackage: firefox-3.0
Uname: Linux birgit-desktop 2.6.22-14-generic #1 SMP Tue Feb 12 07:42:25 UTC 2008 i686 GNU/Linux

[Micah Gersten (micahg)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue for you. Can you try with the latest Ubuntu release? Thanks in advance.

[Micah Gersten (micahg)]

We'd like to figure out what's causing this bug for you, but we haven't
heard back from you in a while. Could you please let us know if you are still having this issue?

[John Vivirito (gnomefreak)]

Was this fixed after restarting firefox? Should have been :)

[Monkey (monkey-libre)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New". Thanks again!