I upgraded my Razr from the 16gb SD that comes with the phone to a 32gb Sandisk to store the rest of my music "locally." Both are cards are class 4 so there should be no speed issues (please don't mention getting class > 4 because they are overkill and not relevant when reading from an android phone). Prior to the SD upgrade the phone was buttery smooth. After the upgrade no change. Then I load a bunch of songs to the card and things begin to slow up dramatically. The gallery, the file manager, Quick Office, etc are all affected but the UI is not. Anything that requires reading the SD card is affected. Did I get a bad card or a bad load? I then follow standard operating procedure (demount-remount, reboot, erase, reformat, check errors, yadda yadda). The card seems fine on PC (15mg sustained read, 4mg sustained write). Yet every time I reload the songs the same thing happens. Slooow Razr. I then recall this happening on my HTC Tbolt. Hmmm. I decide to go back to the 16gb card and load 4000 songs to the stock 16gb card. Razr is slow. Hmmm! I reduce to 3000 songs. Razr is fast again. Put back in the new 32gb card and load only 3000 songs. Razr is fast again. I could be off, but I have come to the conclusion that this must be an issue with how the phone or Android caches the directory structure. Meaning it has nothing to do with the size of card or used space. It seems to be the size of the directory (Number of directories, sub-directories, files and length of names) that is causing the slow down. Has anyone else experienced this?