I had the same problem...new 32gig sd card works just fine under windows, but in my Samsung s2,s3, and EVO it says damaged, or unsupported, etc.... I then read on another droid forum about this issue and here is the easy fix! Put your sd card into a usb reader for mem cards etc. You will notice that your card reader has a drive number like G:, or H:, etc... Make a shortcut on your windows desktop and make the shortcut location as (cmd). You may remember that cmd is the DOS-box command line prompt. Now your shortcut to cmd is on your desktop. Right click that shortcut and select "run as administrator". Now at the DOS prompt type:
chkdsk <drive letter of the sd>: /r
Let it run through it's checks, etc. Once done just pop your sd card back into your phone and enjoy!