SLI Cards one w/ Bridge one without

I purchased a second Nvidea card for SLI. When installing it, I found the 512 card that was installed at purchase does not have the bridge connector on top. There is a card (Credit card type)on the MOBO, and it appeares the SLI is working although slower and some hang ups.

What is the deal with different cards with and without? They are both are 512 nvidea.

I tried to connect Palit 8800gt 512 and 8800gt 1024MB in SLI. Computer see
this cards in device manager, i put sli tape to connect them aswell and
computer dont treat them like SLI cards (dont have in nvidia sli options). i
was reading on nvidia website to use coolbits to change memory size one of
them but it doesnt work. i was reading on forums and looks like nobody
connected two the same cards (G92) with different memory size.

Reply from Palit support:
Dear Sir,
Theoretically, there is possible to do that kind of SLI. We don't set any
barrier in VGA BIOS, but we don't test our card in this way as well.

Can anyone help me in this metter, please?