iPaqs won’t shut down!

We are installing many legacy-free iPaqs enterprise-wide, and are having trouble with them staying on the Shutdown screen. Running Win98 with Novell NetWare, NT for email. Installing the two shutdown “updates” from Microsoft works for 2 or 3 shutdowns, then it goes back to hanging again. Any suggestions were to look next to fix? We’ve already ruled out network scripts, and replaced the anti-virus package.