RAM 8gb upgrade issues please help!!!!!

i recently purchased a 8gb upgrade kit made by corsair from fry's electronics and when i install the the ram my macbook pro 13" late 2010 model wont boot up it freeze's on the apple logo boot screen but when i install one 4gb corsair card and 1 2gb factory apple card it boots up just fine and shows i have 6gb of ram i have tried both cards this way and they are functioning just fine... but wont work together

if anyone has info on what to do please help
thank you

Macbook Pro 13"
intel core duo 2.4ghz
4gb of ddr3 ram (trying to upgrade to 8)
nvidia geforce 320m

I would say there is a compatibility issue not knocking that brand but never had any issue
with Crucial.

yeah im thinking so since it works just fine with 1 thrid party n 1 factory stick but not both 3rd party sticks & ive heard nothing but good things about crucial....

thanks for the input

Take the memory back to Fry's and get a refund. Your MBP should be able to take 8 GB (2 x 4 GB modules). Macs are fussy about memory and since I've never used Corsair memory, I can't comment on whether it's any good or not. I buy my memory from either Crucial or Other World Computing.

OWC has the 8 GB kit for your machine for $112.99. LINK

Could be an issue with the 4GB in a particular slot. Have you reversed the slot you were using the 4GB stick is in while trying 6?

If they won't work together, I'd take them back.

(I am a fan of Corsair - used their high end stuff for many a year building overclocked rigs. Paid a premium for the Corsair that's sitting in my MBP now as they had the lowest CAS rating of any notebook RAM at that time.)

If you bought their "Value RAM" line, I don't recommend that stuff for a Mac. They make some great mid and high end sticks, but their "Value" line is just that - not any better than the no name stuff and Macs in general seem to be a little more picky about their RAM.

yes it works in both slots as well as both sticks separately but just not together idk for sure if its their value line or not i paid $115+tax but im taking it back & will most likely go with crucial instead....

I'd have gone with Crucial if Corsair hadn't just come out with these new sticks at the time I was looking.

thanks for all the help... i went with the owc kit as well as a new hard drive