Start Programs menu freezes

on one of my NT 4.0 SP6a when I go to Start/Programs and select an application to lunch it works fine as long as I select any application really fast. If I stall just for a couple of seconds when I’m in Start/Programs the whole pullout menu freezes and I have to select my desktop and try Start/Programs again.
? ? ? ?
I have plenty of memory and h.d., Anti virus up to date, h.d.’s are not fragmented
Running NT.40 server and IIS 4 with all the latest patches and SP’s