PEP21G6400LL with DG33TL MoBo ?

-Patriot Extreme Performance 1GB 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
-Intel BOXDG33TLM LGA 775 Intel G33 Micro ATX Intel Motherboard

I have an Intel DG33TL MoBo and it supports the following:
1.8 V (only) DDR2 SDRAM DIMMs with gold-plated contacts
DDR2 800 or DDR2 667 MHz SDRAM DIMMs
DDR2 667 SIMMs with SPD timings of only 5-5-5 (tCL-tRCD-tRP)
DDR2 800 SIMMs with SPD timings of only 5-5-5 or 6-6-6 (tCL-tRCD-tRP)
Note

I have 2 x 1GB DDR2 PC2-6400 800MHz (4-4-4-12), 2.2v memory in it, but is running at 5-5-5-15.

Is this a bad thing? I'm not exactly sure on how all this memory stuff works. Is this creating my ram not to be as powerful as it could be? and should be?

I used to have this memory in an ASUS M2A-VM MoBo and the timings were normal 4-4-4-12 and it seemed like the performace was better..idk if it's just me or what.

I also have an Intel Core 2 Quad 2.66GHZ/1066 FSB
with Windows Vista Home Prem 32bit.

What should I do? any suggestions?
Thank you and i'm sorry for the inconvenience.