It is completely possible that the PCI slot is going out. I had a client computer a week ago that kept having Video issues. After some testing we found out that the PCIe slot was shorting out. It destroyed two video cards in the meantime. Thank goodness they were under warranty
If you are not having issues with the wireless card in another computer, I wouldn't recommend using it in the computer that you are having issues, otherwise you could ruin the card.
However, it is likely that you may have an incorrect driver installed? If at all any driver?