Yes 2GB is the limit (in theory) but 'twas always a fussy beast, I did have a couple of small drives that worked but one is borked and the other lost.
Found firmware upgrade that claims it capable of reading a whopping 64GB I was in catch22..
Workaround was to use a 256MB SD card in a reader, and format it in the instrument it's now updating firmware..
Then after a reboot to new firmware it chirpily tells me that my 1 GB drive is unsupported.. too large.. back to SD card for saving screen shots... happy days..