Gino1965, Is your player reading 2GB or still 4GB?
For 1.5 amv conversion you are better off using version 3.68 of the MP3 Player Utilities as it is a little more stable.
You also should install a codec pack.
MP3 Player Utilities 3.68
HERE
K-Lite mega Codec Pack
HERE
For full screen 128x128 you should set the frames rate to medium (10fprs) when converting your amv videos. This will generally fix Format Error Problems.
For wide screen 128x96 you may be able to use the high setting (12fps)
You should also select the "Try other codecs" option at the bottom of the settings window in AMV Converter.