usb flash drives

Hi, is there a maximum size of pen drive the foxsat hdr will accept? I have a 32gb one and every time I plug it in I get the message "cannot read usb drive it must be formatted fat16/32 or ext3" (something like that). I've formatted and re-formatted the drive as fat32 umpteen times but get the same error message. A 4gb drive formatted as fat 32 works fine.

Any suggestions/ideas welcome.