The garbled names you posted indicate that some pins still do not connect properly. Please check the following pins on the edge connectors and slots of the cartridge, plug-in and Retrode:
AD10 = GBA pin 16 / MD pin A27
AD06 = GBA pin 12 / MD pin A22
AD02 = GBA pin 08 / MD pin A26
Please also look for short-circuits on those pins inside the plug-in.
I think AD10 is to blame for getting "...mermo" instead of "...mario" and "...sept" instead of "...sapp", but it might also be AD02. If it were AD02 though, we should only get 8 bytes of the name, and then garbage.
"d" instead of a space (I guess) points at AD06.
Does anybody know a good cleaning method for the slots? Cotton swabs don't fit in there. (I recently used a flat screwdriver to scrape off some oxides, but that's a rather bad method, I guess.)