Hmm, I can duplicate the problem on another PC - ASUS P2B, 1 GHz P3, 384 MB Micron SDRAM, Windows 2000 SP4, F-Prot 3.16b, Nero 22.214.171.124.
There's definitely something wrong, because it takes forever to start Nero Burning ROM. Especially when you first start Nero StartSmart. I've noticed if I wait for half a minute, Nero eventually pops up. Meanwhile, CPU Usage is at full 100%!
I've been using F-Prot for quite some time, but only recently allowed F-StopW to protect the machine all the time. It seems that only Nero has troubles executing while F-StopW is active.