Remember when Windows Phone 7 devices were first launched, users were warned not to change the memory cards inside their phones on their own? And that regular microSD cards could possibly ruin the phone? Everyone was told to wait for certified memory cards to arrive, and now it looks like they’re finally here. The folks at engadget have spotted a fresh stock of certified 8GB Class 4 microSDHC cards at an AT&T store. The microSDHC cards are produced by SanDisk and will go for $32 a pop (8GB). No word on whether other brands or other sizes will be introduced but for now – users who have been afraid to insert memory cards into their WP7 devices have a brand they can trust. How many of you have already upgraded your WP7 phone’s memory with uncertified cards? Have you encountered any problems?