Memory upgrade for Dell Vostro 430

Hi guys.
I was trying to collect as much information as possible before posting here to get the correct answer from forum experts. So here we go.
I'm planing to upgrade memory in my Dell. Here are some screen shots (all images are clickable and will open in a separate window to see full size)
The original memory installed in my system (3):

Technology DDR3 SDRAM
Form Factor DIMM 240-pin
Memory Speed 1333 MHz ( PC3-10600 )
Data Integrity Check Non-ECC
RAM Features Unbuffered
Module Configuration 512 x 64
Compatible Slots 1 x memory - DIMM 240-pin



CPU-Z screens:









I've always trusted Kingston's memory and couple years ago they had my system on their list. Now they don't. I wrote down the number back then (KVR1333D3N9K2/8G) and was trying to find it like that. Turned out that it was discontinued and replaced by KVR13N9S8K2/8. I also called the support number to make sure it will work. The rep I was talking to said that it won't and that they don't support the system like I have any more. OK. Forget about Kingston then.
Went on Dell's website. Put my service tag -> check memory upgrade for this particular system. Here is the screen:



What? Doesn't Dell know what they sold me? Fine. The hell with Dell :)
Went on Crucial. Downloaded and ran CrucialScan. Here is the screen:



The first thing they recommend is again not what I have. It's PC3-12800 instead of 10600 and as far as I understand CL11 is slower than CL9 too. When I clicked "Show all compatible computer memory" I got this:



At least I can see the specs that are the same with what I have. But I'm afraid to buy anything because all the specs were the same on Kingston's website and still they told me it wouldn't work.

I'm lost... What do you guys think about all this?
Thanks for reading.

Do you intend to remove and replace all of the current 3 gb and replace with all new?

Or keep the existing RAM and add more in the 4th slot?

If you replace it all, you could go with PC3-12800 instead of the existing PC3-10600. Slightly faster, but you'd never notice it. Likewise, you aren't likely to notice the difference between CL 11 and CL 9. If the price difference is 5 bucks, I'd probably go with the faster. Ten bucks, I probably wouldn't.

Whatever you do, be sure to get 1.5 volt, DDR3, 240 pin.

Looking at the list, I'd probably go with Crucial part number 4056100 for 91.99; the first one shown. Crucial has good return policies and it's guaranteed to be compatible.

Guys, thanks for your replies. How come the rep at Kingston told me that their memory will not work in my system even though all the specs were the same... Am I missing something? This is the one I'm talking about: 8GB Kit* (2x4GB) - DDR3 1333MHz


ignatzatsonic, I was planning to put the 8GB Kit (2x4GB) and keep 2 of mine. This way I'll have 10GB.