Okay, some feedback about this
(i dont see anyone having this issue? Or noone didnt bother about checking it? :S)
I've done many times a factory reset, rom change, etc... that didnt solve my problem.
"Played" with any configuration file regarding power saving settings, wifi settings, etc.
Let my cellphone chill the f*ck out, without battery in for a day
Finally, i rollbacked, at 2.2 official unrooted (V10G).
Changed ALL possible combinations of my 3 routers having stored in wifi settings!
n o t h i n g c h a n g e d !
When phone is in sleep and changes location, doesnt auto-connect in any of those wireless routers! It only does when i get to wireless settings which refreshes the list, or wait with screen on randomly from a few seconds or till infinite (never).
So, last week, 1st June 2012 i've spoken with LG customer care, arranged a courier transfer for service (not in my city) and waited till 6th june when they sent back my phone.
The authorised service, which does the job for LG phones in Greece reported:
"Wifi turns off when screen off, due to power saving policy"
O, RLY you idiots??? Dont you think i dont know it, or i didnt mentioned that on that f*ckin A4 sized page i've typed out to explain CLEARLY my problem?
Or you think im a retard??
Of course, wifi policy is set to "Never"
LG authorized service center (3rd party company) is totally crap.
I'm going to send the phone again tomorrow.
If they still dont fix the issue, then i'll demand a sure fix the hard way!