Sapphire 2600XT causes DRAM error on X38 Platinum

I have been running my X38 Platinum with a Q9550, a basic 1GB Crucial DDR3 1066MHz (I know I could do with 2) and NVIDIA 9800GTX+ OC and it has been running beautifully, and still does, however, earlier I tried putting in a Sapphire 2600 XT 256MB GDDR3 so that I could use the AVIVO for connecting to my TV, but when I changed out the NVIDIA for the new card the boot stalled, showing "DRAM" on the LED panel. I have since put the NVIDIA back in and everything is as usual, am I doing something wrong? Thanks