CDJ "loses touch" with Slink-e?

I'm running into a problem where CDJ seems to lose communications with either the Slink-e or the CD changers after a while (sometimes ten minutes, sometimes two hours.) The most obvious problem is when running a play list (or shuffle mode), and CDJ stops ticking the track clock (and loses track of the currently-playing track), while the changer keeps merrily playing to the end of the CD, then to the next CD slot, and so on ... The same sort of thing happens with Library -> Search For Discs..., where CDJ "thinks" it's searching through each slot, but the changer stopped moving a while ago (i.e. CDJ says it's searching slot 200, but the CD changer's front panel display is back on slot 42.)

Any ideas?

I'm using CDJ version 1.32, build date 09/16/00, on Windows 98 Second Edition. The Slink-e is version 2.3, and the changers are one CDP-CX240, two CDP-CX400. Each changer is plugged into its own S-Link port on the Slink-e, and the Slink-e is connected to the PC using the original Nirvis-supplied serial cable.

Thanks!