Post date: Apr 28, 2010 5:11:29 PM
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\mailto\shell\open\command\
edit (default) to :
"C:\Users\*username*\AppData\Local\Google\Chrome\Application\chrome.exe" https://mail.google.com/mail?extsrc=mailto&url=%1
This worked for me... found it myself by the way ! :-P First time I'm able to do something like that :-)
Source of above information: http://www.google.com/support/forum/p/Talk/thread?tid=5630cbddac6bbb47&hl=en