No. You may be misguided by my poor solution (DOS-form path).
Rename "firefox.exe" to "firefox2.exe" and set it to the Web Browser
setting, this solve the problem too. (not sure side-effect, so I didn't
describe this)
I'm not sure but only default installation path ("C:\Program Files\Mozilla
Firefox\firefox.exe") seems to cause this problem. Other installation (I
have C:\usr\FirefoxPortable\FirefoxPortable.exe for 3beta5) works fine.
Oops, I've found "C:\Program Files\Mozilla Firefox\FIREFOX.EXE" works for
me...