Was trying to do a little research last night, but didnt have much luck. They may only have tested the product with cards up to 2GB in size so thats all they can really claim it to work with. SD Cards larger than 2GB may not have been available when they were testing the product... Can't say I even recall seeing a SD card bigger than 2GB.
Would be nice if it did MPEG4, but not sure its ready to go into a product that small at a reasonable price. Might cut the filesize in half or so (double the recording time).
jc, let me know how the image quality is when you get it...
