Another Memory Question?

As stated before I purchased 2 512mb sticks of Pny memory. It will only read 512mb via 256mb per. I have changed slots etc.
Tonite I ran the Hardware Test again and found this " Error detected at start-up".
Also /0/2048 DIMM/J12.......Any suggest?? I am on the verge of taking it back to comp for another if all else fails. Thanks In Advance

 

Yea it is on the box that it is 1GB Kit @x512mb modules for G5 Only! Yea I also was suprised when I looked in the locked memory box and seen that price for it. A man in front of me purchased two for that price leaving me the only one left. It also has a rebate of $30.00. On my rebate it states that it was a one week pny deal!
Only if it would work IT WOULD BE GREAT!!!!!!!!

 

Yea I think returning the memory is the best thing to do! I just wanted to make sure I was not doing anything wrong.