shshsh

I checked all USB ports on that machine. The behaviour was consistent with all of them: Dongle directly on the USB port without any extension cable works fine. Dongle on the shielded extension cable works fine. Dongle on either of the two other cables results in that flaky on-off behaviour. In the meantime, somebody told me that those extension cables might be out of spec - too long for what the USB standard specifies. One way or the other, all other USB hardware I own works nicely with either of them - on three different computers. Nevermind, one approach that works is good enough for me, and I have that now. ;-)

OK, here are the logs: http://www.suse.de/~sh/codemeter/CmDust-Logs.zip Sorry for the delay. It's been really busy around here.

OK, will do. BTW it's a hardware problem, not a windows problem. The dongle showed the same behaviour under Linux - I got lots of "connected" and "disconnected" messages there, too (in /var/log/messages).

I'll check that when I next get to that machine (next weekend).

I also found out the hard way last weekend that USB extension cables can make a real difference. Plugging my dongle into such an USB extension cable gave me constant "ding" (USB device recognized by Windows) and "dong" (received USB device disconnect event) events - the dongle was visible for some seconds, then it was gone for some seconds, etc.; sometimes it would stabilize, sometimes it wouldn't. I've been using that very same USB extension cable for my USB stick, my external USB hard disk, my digicam, my USB multi-card reader, my USB MP3 player without problems since over one year, so the cable was the last thing I suspected. Yet my SB Pro PE dongle was recognized rock-solid when I plugged it directly into a USB port in my computer's case (had to crawl under the desk for that, that's why I have that extension cable) and even when I plugged it into a somewhat more expensive USB extension cable with shielding (that wire mesh stuff around the cable - you can sometimes see it with transparent cable isolations). Bottom line: If your dongle is flaky using a USB extension cable, try plugging it into the USB port in your computer's case directly. It might help.