I don't have Sound Forge into Sonar's menu (I did not the regedit trick) but anyway if you need to run Sound Forge even not as Administrator there is a different trick:
just remove the "License" key at the end of this regedit path:
HKEY_USERS\S-1-5-21-955843276-3736432714-3134191713-1001_Classes\VirtualStore\MACHINE\SOFTWARE\Wow6432Node\Sony Creative Software\Sound Forge Pro\10.0\License
(please note that the number after HKEY_USERS differs from computer to computer, so look for the correct number in yours...
I also created a simple .reg file with this content:
Windows Registry Editor Version 5.00
[-HKEY_USERS\S-1-5-21-955843276-3736432714-3134191713-1001_Classes\VirtualStore\MACHINE\SOFTWARE\Wow6432Node\Sony Creative Software\Sound Forge Pro\10.0\License]
and .... when Sound Forge is not starting I simply click to it and everything works.
I hope that this could help you.
Regards,
Giorgio