I'm running SME 5, and connecting to it with two Win2K Pro workstations. With both systems I've been able to view all the ibays, and read/write isn't a problem either. In fact, as I type this I'm copying 3 650 MB ISO images across to my home dir on my SME 5 box with no problems. Permissions seem to work as well, I can only see the iBays that my userid has access to.
I didn't do anything special to the configuration, just made sure that my workstations belonged to the correct workgroup, and that's it.
Are your copies of Win2k up to date w/the latest MS ServicePacks? I know at one point there were some filesharing issues with win2k, but the packs supposedly took care of that.