We strongly recommend the update to Firefox 3.0.11.
Firefox 3.0.11 fixes several security issues found in Firefox 3.0.10 (4 Critical, 1 High, 2 Moderate, 2 Low):
MFSA 2009-32 JavaScript chrome privilege escalation
MFSA 2009-31 XUL scripts bypass content-policy checks
MFSA 2009-30 Incorrect principal set for file: resources loaded via location bar
MFSA 2009-29 Arbitrary code execution using event listeners attached to an element whose owner document is null
MFSA 2009-28 Race condition while accessing the private data of a NPObject JS wrapper class object
MFSA 2009-27 SSL tampering via non-200 responses to proxy CONNECT requests
MFSA 2009-26 Arbitrary domain cookie access by local file: resources
MFSA 2009-25 URL spoofing with invalid unicode characters
MFSA 2009-24 Crashes with evidence of memory corruption (rv:1.9.0.11)
The sooner… the safer!