SR 290 series memory..is CL/CAS an issue while upgrading?..

Hi guys..I've ordered an SR290 series customized from sonystyle. I have it configured with Vista 64-bit and 2GB (1GB X 2) memory..they will be putting in DDR2-800 / PC2-6400 chips..
Well, I would like to upgrade to 2GB X 2 (total 4 GB)..
Please let me know whether this model will work fine with the notebook..
You can see the notebook memory I'm talking about on ocztechnology dot com..I'm sorry, since I'm a newbie, it's not allowing me to post external website links on this thread..but OCZ only make one particular model of notebook pc2-6400 type of memory..so, wouldn't be hard to find on their site..

I don't know what all the CL/CAS and stuff is for..all I know is this OCZ one is also DDR2-800 / PC2-6400 type of notebook memory..I'm just worried of the other factors..like unbuffered/1.8 volt stuff/cl-5-5-5-something..

Thanks,
srxbr

 

Sony's default installed memory is 6-6-6-18, but I installed an additional 5-5-5-18 module @ 1.8V and it all worked fine.

 

So, this OCZ which I'm planning to order, well, if my original SR290 chips are 6-6-6-18 from factory, and I remove both and put in both new ones which are like 5-5-5-15..will it work ?..
-srxbr