Comments:
MSNIM handlers are useful, but It seems that these protocols are not
working in Firefox
It seems that FireFox will just check HKCU and HKCR for the handlers,
whereby MSNIM is registered as a Protocol Handler in the registry :
HKLM\Software\Classes\Protocols\Handler\msnim
I really appreciate if FireFox scans through
HKLM\Software\Classes\Protocols\Handler\ too.
and here is some reference to the problem
http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.windows.live.messenger&tid=724f6552-b380-4b9e-a75c-0a9109e96744&p=1
Browser Details: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1) Gecko/20061010 Firefox/2.0