T30 PC Card Problem??

[Bg357]

I recently purchased a T30/Win2K in excellent condition, everything seems to work great except for one problem I'm having with the PC card slots.
I've had several Toshiba laptops but this is my first IBM. I've only ever used PC card slots for flash memory adaptors, such as Compact Flash & Secure Digital.
So here's the problem, my CF adapter with a 512mb card installed will work in either slot, no problems. My multi-card adapter with a 512mb SD card installed will only work in the bottom slot. When I put it in the top slot, the computer knows something is there but doesn't recognize it as a disk drive.
The serious problem occurs when I put a 1gb SD card in the adapter. Doesn't recognize it as a drive in the top slot and in the bottom slot it seems to work until you try to access any information on the card, at which point the whole system locks up. I've tried to access good information on the card and I've also reformatted the card in another device and tried to write data to the card with no luck. The last time I tried, the system had a freakin' heart attack, wouldn't shut down, after I forced it to shutdown it wouldn't restart. I shut it down again, unplugged it, waited awhile, said a few prayers and it did start up finally. All the icons were moved around but at least it was running.
This is a good card, Sandisk Ultra II, same as the 512 card. Otherwise, the computer runs rock-solid without any glitches so I'm really surprised by this situation. Any feedback would be greatly appreciated.