SMS1.2:Clients not reporting inventory

I have an NT domain with the PDC as a logon server and all other servers (all BDCs) as SMS Clients reporting to the one logon server. (The site server is in a different domain). Problem is that, while the servers run their inventory scans as scheduled, the .RAW files are never sent back to the logon server unless the client server is logged on and runsms.bat is called.
I’ve tried scheduling an AT command to run daily, the command is \\\sms_shr\runsms, but no go – .RAW files still sitting in ms\sms\invdata.
Anyone got any ideas?