Hi Brett,
I don't think it will work to a mapped network drive, it's in the doccumentation.
Record to a local drive and then share that directory, that directory will be visible to other mce machines if you add it as a video directory.
Like BigAl said: you cannot record to a network drive - local only. The reason is that the network cannot be relied upon to have 100% uptime and 0% errors; therefore, it can't be used as the RecordPath (and, with that, the location of the LiveTV buffer.)
Since space is your concern, you can use Robocopy (included in the Windows Server 2003 Resource Kit Tools) to move your completed recordings to a network share.
HTH,
~Chris Cupler [MS-MVP (Windows Entertainment and Connected Home)] 'nearly every day of my life is some kind of computer hell'My system specs