I have been using the Tripplite cable for over two weeks and my problem has not recurred (fingers crossed). With the old cable, the printer would be taken offline at unpredictable intervals. The only workaround was to unplug the cable from the Apple wired keyboard (old style with plastic keys) and plug it in again. This is an uncontrolled experiment, however. When I received the new 6-foot cable (which I had thought was long enough), I found that it didn't reach the keyboard. I had neglected to measure the length of the old cable, which is 10 feet.
Fortunately, the new cable was able to reach my Tripplite USB hub. At this point, I don't know if the issue was with the cable or the USB connector on the keyboard. Another observation is that dropouts from my Thunderbolt-connected external drives (plugged directly into the iMac, not into a hub) seemed to have stopped. Coincidentally, the acquisition of the new cable occurred at the same time that I installed the Supplemental 10.5.6 Update (probably irrelevant).
At any rate, everything seems to be working well (and I hope that I haven't spoken too soon).
As to Belkin, I had had one of their USB hubs and it failed after a year. I replaced it with Tripplite and have had no issues.
