Is is always the same keys?
Are those note numbers (G11 etc.) correct?
Yes, as Clemens suggests, the note numbers do NOT look right. Also, the Velocity values are garbage, Vel is always 0-127, where 0 is OFF and 127 is max.
Are you using one of the 'cheap' USB/DIN connectors. Certain ones just do NOT work correctlt, and they garbage the data passing through. Please send pic of the cable/interface, or just try another one.
OK, it's probably the USB/midi connector. There are some on the market, mostly made in China, that use a specific circuit and a specific IC inside, and there is something seriously wrong with it. They work in some circumstances, and NOT in others. Evidently, the thing can be 'fixed', but it's not an easy job. Check on web regarding faulty USB/Midi connector/interface. There have been previous posts on this forum, and more in other places, but as usual when I try to look specifically for this I don't find it. One name 'DigitalLife' has been mentioned.
The note G11 means the note G in the 11th octave (above middle C ?). You've got THAT big a keyboard? Picture of THAT, please!
Yes, that Midi <-> USB device is certainly suspect. I'd try to find another, There are ones that work properly for a little more than those cost.
As for fixing it, I'd suggest that no, it's not something to try unless you're really into fixing things. Prob not worth the trouble. Try to find a branded connector, I've seen mention of some brands. Basically, ANY branded one will be a much better option.
Yes, G11 will not be available with your keyboard, unless there's a LOT of octave shifting available. Actually, I'm not even sure G11 will be within the range of human hearing. Is it? Prob not in thw range produced by any normal instrument. The midi note number would go up to 127 ONLY, while G11 would be 98 (hex) which is 152 decimal which is 3 octaves higher than the usual highest note - hmm, might be audiable, but maybe not with my ears??
I've never used this type of thing. All my midi stuff connects happily using the standard DIN midi cables. I'd tend to be suspicious of the USB things on timing grounds anyway.
I don't know what sort of price you're thinking of, but there's a Roland UM-ONE device very similar to what you've got (but looks more professional) for £35 or thereabouts ($59) but may be better prices on the web. If it's Roland it should be good. There's a cheaper device, similar, by M-Audio, named 'Uno', that should be somewhat less, and I think I've heard of M-Audio regarding other devices.
In the case of previous discussions on this forum, where people have described the problems they've been having (like your problem) when they've reported back that they've got a better interface, it has worked perfectly and all their problems have GONE. So prob anything £20 or more will be better!