Could not install the custom actions. The object could not be found

I have Office 2007 and recently I started getting the error written in the title whenever I go to work with a message. This error comes up whether I am composing new, replying or forwarding. I dont know where to troubleshoot this issue. I have searched for this error on many websites but I cant find any solution at all. Can anyone please help me out? Thanks.

It seems to me that there is something in the active profile that is messing up things. When you make a brand new windows profile, you will not get the error. I didnt find the exact problem causing this error and I dont have time to try and identify it. So, I just created a new clean profile and backed that up as a copy and if I ever should get the error, I can revert to the known good profile.

For Vista or Windows Server 2008 users
Kill outlook.exe
delete \Users\[user_name]\AppData\Local\Microsoft\FORMS
restart outlook

For XP users,
use path D:\Users\[user_name]\AppData\Local\Microsoft\FORMS

This should resolve the problem.

Here is the fixed for Windows XP and it worked just fine on my PC:
Do the Windows search and you'll find this FRMCACHE.DAT under C:\documents and settings\yourloginusers\local settings\application data\microsoft\forms\FRMCACHE.DAT (go ahead and delete that frmcache.dat) then restart OUTLOOK, it shoud work fine, now.