Old thread, I never did get back to you, since I returned the bass to the shop I purchased from.
But I did check everything David and Mica pointed out: It was same on both pickups, saddles are tight, and no 'deadening' of string vibration. I bought one of those "magnetic field viewing film" to see whether pickups are covering the G string, and it was perfectly covering G strings (perfectly positioned in the middle to cover all strings). I did try the heavier gauge, didn't notice any difference...
So I returned the bass, thinking it was something wrong with the bass.... shop did acknowledge my issue, and they tried to fix, but no avail.
Then few months passed, I kept in touch with the shop and they still had the bass, and one day, someone walked in and tried out the bass, then DS-5 wasn't working.
So they fixed it, replacing something inside (blue capacitor-looking things), and that fixed the G-string issue.
I have no clue how this could fix the issue, maybe it's just in my head, I don't know, but G string sounds 'balanced' and pretty bright (not as bright as my Europa).
I really liked the bass to begin with, and now with the issue gone, and shop lowering the price even further, I re-purchased it
I don't know/understand how this could be the issue, but since my bass is old, and could only run neck pickup with batteries, I never actually tried with just batteries... that might have narrowed down the source of problem...
Anyways, thank you very much for the support!!!
Takeo