greetings /g/,

I recently came up on a 1gb corsair stick, CM2X1024-6400 ver5.1
it has 5-5-5-12 timings @ 800MHz
the ram i currently have in my system is this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231098
and 2x512 (two of the three that came with the comp)
All DDR2-800, but they have 5-5-5-15 timings.

tl;dr
is there any potential problem with using ram sticks with different timings?

Also, how hard would it be to unlock my bios or have it unlocked? I'm tired of not being able to change advanced options.
I have a very much changed HP m8100n w/an ECS Nettle 2 mobo.
inb4 pre-builtfag
=]



best regards,
Dr. Ugs, PhD.