FYI WinXP and SanDisk CompactFlash reader

Just FYI in case anyone else has encountered similar weirdness.
My WindowsXP Home system recently started taking 5 to 15 minutes, yes minutes, to bootup. It would just hang with a black screen while it did its nails or something, then eventually start up.

I narrowed it down to a new SanDisk USB 2.0 model SDDR-91 CompactFlash reader.
If I unplug that everything is fine, or if there's a memory card in it again it's OK. But leaving it plugged into the USB w/o a memory card in it and it's snooze time.

The www.sandisk.com site recommended disabling "legacy USB support" in the BIOS and the Microsoft site's "Q282195" says that option isn't needed for XP systems. So I disabled that but no difference.

SanDisk does it again!

I'm still plugging in the flash reader only when I need it, and unplugging when done.

But, I've recently upgraded my USB pen drive to a SanDisk "Cruzer" micro SDCZ4-512.
Now I find that if I boot the PC while that's plugged in it takes about 15 minutes,
while the SanDisk LED flashed slowly on/off.
Then, once it has booted up, if I run my home-made file backup program that accesses the flashdrive, it hangs helplessly.
I use many USB devices, but only the SanDisk seems to confuse the PC.

Note, no such problems with my Windows98, just the XP.