I asked this question some time ago but never received any responses, so, as it's still a problem and others too seem to be suffering from it (look on google groups) I though I'd re-post it.....
We use the usual single "Root" share containing all our users home directories and define the mapped drive in AD (win2K3 domain) as \\<server>\home\%USERNAME% (where home is the actual sharename on the server).
On Win2K and XP SP1 clients this is fine the drive maps correctly every time the user logs in, BUT on XP SP2 the drive is intermittently mapped incorrectly. When it maps wrongly, the HOMESHARE and HOMEPATH variables are incorrect - in fact exactly as they used to be in NT4 (HOMESHARE = \\servername\home and HOMEPATH = \%username%) When it maps correctly ithey're "\\servername\home\%username%" and "\" respectively.
I've tried mapping the drive in a LogonScript called by GPO AND defined in the users profile in AD all with the same result. I have also set the option in GPO to force the Win2k "deep mapping" and this has made no difference.
Any help/ideas would be greatly appreciated.