iMac G5 RAM question... 64 or 128?

I have a 2ghz G5 iMac (ALS), with just 512mb of RAM. I've been wanting to add more for a while now and I stumbled upon this article, which basically says if you match the two DIMM's, it runs 128bit instead of 64. I decided since I work with audio in Logic and sometimes some video, I'd benefit more from running at 128 over adding a 1gb module instead of only another 512.



http://docs.info.apple.com/article.html?artnum=300082



Now I tried to make sure I got a matching DIMM, thought I had it all right but once installed it says this:



DIMM0/J4000: Sizet512 MB TypetDDR SDRAM SpeedtPC3200U-30330

DIMM1/J4001: Sizet512 MB TypetDDR SDRAM SpeedtPC3200U-25330



Everything matches up just fine, EXCEPT the 5 digit number at the end, and of course that number isn't listed on the RAM package anywhere or in the descriptions online. Looking closer at that article, I'm pretty sure I'm screwed and still at 64bit. Oh well, my brother has the exact same iMac purchased at the same time so maybe I could swithc for his, then it should match.



Could someone inform me as to what the 30330 and 25330 are referring too?



Sorry for the rant, I more or less answered my first question on my own, but I wrote it all out so I'm going to post it anyways.

Thanks!