Question about graphic card power connector

[kr105]

Hello,
Today i bought a new hd5850 (EAH5850, the Asus one) and i was planning to add it to my minning rig. I noticed that on my PSU only left one free 6 pin PCIe power connector and some free molex, but the problem/question is:

The graphic card needs a 6pin connector and a 8pin connector at the same time, but currently i have one 6pin connector and one molex to 6pin connector, both connectors fit in the card but the second one leave 2 unused "pins" that the 8pins connector should provide. I turned on the computer and it went fine, but i'm worried about the 2 free pins.

I need to buy the 8 pin connector or i can feel safe with the current config?

[LegitBit]

.... run it at spec, if the card manufacturer decided the card needed 8+6 pins then that is likely the best way to run the card.

[MaGNeT]

.... run it at spec, if the card manufacturer decided the card needed 8+6 pins then that is likely the best way to run the card.

True, but if you underclock the ram to 300Mhz and undervolt a bit, like I did, I guess it doesn't really matter.
If it works, it works...