Motorola Droid X :: New SD Card Keeps 'freezing' Phone

I have a Droid X and I recently decided to upgrade my sd card to a PNY 16gb card. For some reason, every time I add music to the card I attempt to play the music and it might work fine but after a few songs, the phone slows down and freezes. I've added music to the card a few different ways and I keep getting the same results. For instance, I initially put the card in the phone and formatted it and connected it to my pc with the usb cord and transferred songs that way had issues. Then I used a card reader and formatted the card on the pc, loaded up songs then installed the card into the phone had issues. The only time I had a little 'success' was when I added songs via usb to the card little by little. I added 2 album and used it for a little bit and it seemed fine. Then I added 2 more albums and it seemed ok. By the time I hit about 10-12 albums it got bogged down and the phone froze up on me. I don't know if this matters but in each case I'm just creating a folder called 'Music' and I put all the songs into it.

I'm not sure if the 16gb card is too 'big' or if maybe the type of card I have is wrong. I've also read some stuff about 'media scans'. Does the phone automatically scan new files that are on the sd card and by adding too many at a time the phone just slows down to a crawl?