I have been using an Ambicom since I got my Zaurus December 2007,and I've just started to see the issues as well.
Screen washes out to white, works again when card is removed.
Connection drop, zaurus responds very slow, works fine again when the card is removed
Not detected, remove and reinsert a couple of times, it works again.. then repeat from the top ...
Is this a bad quality card or something ?