I've now had two 1 gig Kingston CF cards break and stop working, the cards appear to short-circuit internally, heating up when placed in the card reader. All data is lost, since Kingston won't try to recover data if RMA'd I ended up taking them apart to see if there was any obvious problem I could fix.
Needless to say taking CF cards apart invalidates any kind of warrenty but for the £30 odd they cost it seemed worth a punt if there was any chance of getting the images back off the card. After taking both failed cards apart the problem didn't magically fix itself (suprise!) but I'll post some pictures showing which internal chip gets hot in hopes it helps someone else.
I'll post more on this later but looking on google I couldn't find anyone with similar issues and I find it hard to believe I'm the only one who has seen broken Kingston Compact Flash cards.