I've tried what you said and still no luck. Maybe the devil is in the details, so here they go:
1. Downloaded pcmcia.zip from ftp://ftp.support.acer-euro.com/notebook/travelmate_8100/driver.
That's for Windows XP. If there is anything wrong, this should be it, as what I'm installing is the PCMCIA drivers, not the memory card reader, but anyway...
2. Tried to update the driver (the O2 micro that showed a yellow warning in the device manager) by pointing to the extracted folder but since what was installed seems was newer, that didn't work.
3. Told it to pick up the disk from the manufacturer. That found the .inf and installed the drivers.
4. Tried at that point with a memory card and no luck. The PCMCIA adapters (3 of them) do not show now a yellow warning (before there was one with a yellow warning), but under Other devices there is the Base system device (with warning sign) and another O2 Micro with warning sign.
5. At this point Vista is asking to install drivers for new hardware found, so I let it. After it is done it has added the O2 Micro device under Other devices to the Smart Card readers branch, with the full description of O2 Micro SmartCardBus SmartCard Reader.
6. Try a memory card and no luck.
Other things that I can try are to now tell the O2 Micro SmartCardB... to update from the downloaded pcmcia.zip... but thought I would post first.
Update: Tried the last thing, updating the O2 Micro SmartCardB... with the pcmcia.zip drivers and after forcing it, it went ahead. Still no luck. Driver version for the O2 Micro SmartCardB... shown is 126.96.36.1992, date 25/10/2004. What's yours, JRSCCivic98