Hi all,
I had troubles with the Mambo native Shout Boxes so I threw together this module to display Grudges Ultimate Shout Box in Mambo.
You can download this via http://shovelbums.org/content/view/120/481/
I can't vouch for the bullet proofness of this module. I have never wrote one before and used some others as a template but it installed with no problems on my site.
I also announced this on the Ultimate shout Box topic page at:
http://www.simplemachines.org/community/index.php?topic=8415.msg279399#msg279399
My $.02 to help generate more interest in using Mambo and SMF ;)
R. Joe