Gatech,
Did your player come with a sample video? If you did copy it to your computer and open it with AMV Player, while it is running right click on the picture and choose properties. You will then see info on the size and frame rate like this.
If your sample is 160x120 then you should use Version 4.00
If it is 128x128 or 128x96 you can still use Version 4.05 but you need to go to the AMV Converter folder and open the AmvTransform.ini in notepad and change the line CHIPTYPE=1 to CHIPTYPE=0, this will unlock the size settings you need.
Hard error when you try to enter the radio function could indicate that your player is not fitted with a radiop chip or if it is the chip may be faulty. This is a problem you should take up with the seller as it is not something you can fix within the firmware.
If your player is new I suggest you extract and repair the firmware from your player using s1fwx
HERE and you will find a guide to how to do this in the Knowledge Base
HERE
By the way I think your English is great unlike my Spanish
Espere que esto ayude y dé la bienvenida a mympxplayer.org