SCO 5.0 / On-Line 7.10.UD2 -- system slows to a crawl

Hi, I'm out on the bleeding edge of technology here, running SCO Unix 5.0 (also known as Everest or SCO 3.2.5). I've received the latest SCO port of On-Line, version 7.10.UD2. My problem is, after running a few disk-intensive queries (cursor selects from ESQL client running on the same system as the On-Line server), all of a sudden my performance DROPS drastically. The DB server keeps on running, but my queries take as much as 200 times longer after this "slowdown" occurs. Restarting On-Line makes the problem go away for a little while. One symptom that Informix Tech. Support has noticed is that SCO's "sar -u" command reports that the CPU is 99% idle after this slowdown occurs. My question is, has anyone else had problems with SCO 5 and On-Line? Everything seemed OK with SCO 3... Has anyone had success with SCO 5? I would be very interested to hear about some successful or unsuccessful configurations. Thanks, Ernie Daniels