This is just confusing. Works fine for me. I just grabbed it to see and put it on with no special patch or anything. Is it that it does not save? What was the problem here? I would love to dispel this evil myth about the G6 right now. There is something very fundamental that you guys must be doing wrong.
This all confuses me too, I've never had problems either with my (chinese) G6.
I often read about people having problems and I wonder whats going wrong, when I have the same games working fine.
...And I've never upgraded past beta-firmware - I flashed it straight to the (english&chinese) beta fw when I first got it. I'm not saying that's the answer btw, don't go changing firmware to beta expecting everthing to start working. I can confirm that the firmware upgrades have NEVER increased compatability - it is the U-Disk loader (patching software) that contains all the improvements, just make sure that that is up to date and don't use any special tricks when transferring games.
Another important thing is to unzip GBA games first - and don't compress them with U-disk if they have problems (u-disk compression seems about 50-50 - I don't bother with it). And definately don't try to use u-disk to compress a rom
.zip - it won't work.
NDS games all seem to work with 'trim' enabled, but I don't bother with any other options.
I don't know if this will be any help.
[edit] Oh! and my DS is NOT flashed (using passcard 3), if that makes a difference.