DDR Ram issues upgrade

Hi All
Ok i have bought 2Gb PC2700 DDR Memory RAM DDR333 333MHz 128x8 2x 1GB UK.
before i bought the modules i sent the shop an e-mail with my motherboard details to see if it was compatible
Motherboard is a Asrock K7S41GX chipset 741gx.

When i recieved the modules i installed them both as normal, Thats when the problems started, my bios would only recognize
Slot 1 512 DDR 333MHz
Slot 2 512 DDR 333MHz
and in windows I had 1Gb. So i sent another mail saying i have a problem.
On the modules it states 128x64, but on my order form states 128x8 (not sure if thats the problem).any way

I then got mail back saying i must run my index finger and thumb along the gold contacts as there could be microdust on them, did NOT do as unsure,
they go on by saying install 1 module at a time.
But every time i did this Windows would just keep rebooting, But windows would boot normal if the both modules were installed.
I also checked my bios to see if it needed updating, my bios is P2.80 and the only 1 i can see on AsRock website is the 1 am running, so i guess i dont need the flash update.

As am not a computer wizard i need some help. So pls can any 1 help me regarding this matter pls
ive never known that buying DDR ram could be so stressfull

Go into the bios and reset it to the default it then should see the 2gbs of ram.

Sounds like one of the sticks has high density chips on it, they are sometimes not compatible with some older MB’s (mixing high density with low density).

SiS741GX shouldn’t have issues with 512Mb memory.
I’ve run a SiS735 board with Corsair Value RAM PC3200 (400Mhz) 512Mb without hassle and it shouldn’t be that hard to find in the UK (Crucial should be fine too). Could be the board itself though, it’s very old and ASRock didn’t exactly make rock stable motherboards around 2004.

Diizzy ive not got a problem with 512 sticks. its my bios reading 1gb as a 512mb, and yes i did reset my bios to default settings, and it didnt work,
now talking about HD, apparantly my board does support high density as read on other forums but not quite sure if this is true,

has on the modules it says on the Void sticker 128x64 but on the chips it says 128x8, so am not sure if these are not genuin sticks

can some 1 explain wot this means pls

Return them and ask for something else