The issue with remote access to the dashboard or home computers is that you must be running Internet Explorer on a PC for ActiveX controls to run. It will never work on a Mac (and I didn't think a Mac would even show as available for connection, though I
don't have one to test with). Also, are you trying to connect to your Mac from your Mac? That also won't work, and shouldn't work with a PC either.
As for backing up to your server with Time Machine, I assume you have OS X "Lion" installed? When Apple released OS X "Lion", they changed the protocols slightly and broke network backups to non-Time Capsule devices. They've been doing this fairly consistently,
and I sort of suspect that it's intentional on Apple's part. Eventually NAS manufacturers will figure out how to support Time Machine backups again, then Apple will "improve" Time Machine, etc. In any case, it's really not Microsoft's fault it doesn't work
right now; they're behind like all the other NAS vendors.
I'm not on the WHS team, I just post a lot. :)