F1-4000USU2-2GBHZ RMA problem with memtest

So I RMA'ed my G.Skill ram back to obviously G.Skill and the guy tested my ram for 7hours + and reported no errors. He showed me a screenshot and he was using the Windows version of memtest. I clearly stated that my ram had problems in memtest+86 the dos version before sending it over. I re-stated this point again and he said if we do not find any errors on the windows version we will not test memtest+86. Well, I just don't know. I thought that the dos version isn't as vigorous as memtest+86. I remember individually testing the ram one stick at a time and in each slot. All slots and both ram sticks had atleast an error. The only thing I forgot to test was putting a different stick of ram into my mobo and testing to see if it was the mobo problem. BTW I was testing everything at stock

Sigh.

EDIT: this is the email directly copied and pasted

Sorry, we don't test memtest 86+ now.
Because it's more important to run in normal OS.
Only when there is error when running OS, we'll run memtest 86+ to find the
bad chip.

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By stock do you mean, everything was set to auto or you set it yourself, because I know that my board will set some unpostable defaults for my ram.

Avg said:

By stock do you mean, everything was set to auto or you set it yourself, because I know that my board will set some unpostable defaults for my ram.

Click to expand...

Well I tested it an age ago but I recently sent it in for an RMA. However I do remember trying it by SPD (auto) and also setting the values myself (atleast the ones that I know of which I think was half of the settings in the bios, cause I don't know each and every stock setting and the ones I didn't know was set to auto of left by default)

you should have cleared the cmos and let the bios find the defaults itself. Ive had problems with my G.Skill on my DFI board. ive played with all the lesser timing and more complex options in the RAM menu of the BIOS before, and had it not work stabely. When manually changing back those timings to the default values before i played with them, i can never get it stable again, even though those settings were stable before i played with them. The only thing i could do that would work would be to clear the CMOS.

hmmm... but i just can't believe that they won't even check memtest+86 and instead use the windows memtest.