I think it is now time for Craig to get rid of the BLU firmware from a BLU+ Purchase...
Basically:
Gamepark have made changes to the hardware of the original Gamepark BLU in displaying stuff on the LCD.
We have called the new BLU's with these changes BLU+'s.
Lots of programs/firmwares and games (etc...) which were written for standard Gamepark BLU's/FLU's/non-FLU's will not work on the new BLU+'s until they are rewritten.
This means that the majority of Firmwares here will not work on BLU+'s yet.
The firmware which was on the disk GBAx.com supplied you with was for a standard BLU, while yours is (very) likely a BLU+.
That is why you are seeing a grey and black line.
You will have to reflash the original BLU+ firmware onto your Gamepark.
The Firmware can be found here:
Here.
You will have to flash using
this guide.
MAKE SURE YOU USE NEW BATTERIES!
If as you said you can not load any programs on your GP32 you will have to flash using a JTAG cable.
These are hideously difficult to get hold of, (usually you have to make one yourself).
You will most likely be able to find someone to help you out here (or who you can borrow one off).
Or you could complain to Craig, if he hadn't warned you of the consequences of flashingyou BLU+ with the BLU firmware on his supplied disk.
<...few>
edit: it seems everyting else is working fine and you will not need a JTAG cable (thank god!)...