Apparently the Samsung Focus from the line of Windows Phone 7 series has a picky appetite when it comes to it’s micro sd cards. The Focus has some issues working with just simple normal micro sd cards for it’s memory expansion and usually only wants to take micro sd cards which are optimized for Windows Phone 7. Most other phones do not have this sort of problem when it comes to memory expansions. Especially Android devices, which are extremely popular yet do not require specialized memory expansion. This little issue has been known for quite some time so it is a good thing that AT&T has issued warning to Samsung Focus owners to not buy micro sd cards that are not optimized for Windows Phone 7. Hopefully they will be able to make it so they will not need to use special micro sd cards.