If anyone else is having issues using Rendezvous with Asante Intracore switches, you are not alone. I have been working on this for the last week and have talked to Asante on several occasions.
It seems as though there is in issue with the way the switch's code handles IGMP snooping. There is currently an unsupported, not really documented fix. Asante promises a firmware update ASAP. If anyone wants the fix, please let me know via the comments and I'll send it to you. Again it is unsupported and doesn't survive a reset, but it does work.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020830060829470