Excerpt from Nesivos:
"avast! AIS 7.0.1456
Windows 8-RP x64
Mozilla Firefox 14.0b9
Shockwave Flash Plugin 11.3.300.262
No problems
"
I don't know where you got Firefox 14.0b9, but I just searched their web site through and through, and the latest version I see available for download is 13.0.1.
I also don't know how you're running Windows 8 since it hasn't been released yet, unless in both cases you are part of some beta test groups. How did you come by these versions?