Well, the vendor from which i did order the boards, did refund me.
So i did order a two 4GB A versions from different vendor, works flawlesly! Chips on them are from hynix.
My quess is that vendor has messed and switched dram chips on silkscreen printing. Or that producer has been viktim of forgery, wouldn't be suprised if that is the case.
Anyway, end of the drama from my part.