The Samsung Focus's microSD slot has always been an odd little blip on the spec sheet, since it's only kinda-sorta supported by Windows Phone 7, and now it looks like it's causing more trouble than it's worth: Paul Thurrot says AT&T's telling employees not to install anything in the slot because of reliability issues, and that Microsoft is working on the problem. Now, we've had mixed experiences using the microSD slot ourselves, and we've been told by numerous sources that AT&T and Samsung added the feature without too much encouragement from Microsoft, which told us at MIX that expansion
