Best Practices

Havent really come across this as I normally work with the English language packages only.

Got an vendor Windows Installer package, cracked it open with Installshield/InstEd! and it has PRODUCTCODE 123. I install it on a computer with the O/S EN locale and PRODUCTCODE in Progs/Feats = 123. [me: yay]

Installed it on another computer with the O/S RU locale, so changed in Control Panel etc, installed the package and got PRODUCTCODE 456, was expecting 123. [me: waaah?]

The package supports (Summary Information Table) TEMPLATE: 1033,1049,1040,1029,1034,0

Question: 
Shoudnt the product code be 123? Since is set in the package Perperty ProductCode?
I had look for other embeded MSI's, none.
Could be a CA to change it? -that would be weird, but not surprised.

I had a look for more info in regards to PRODUCTCODES and multi lang support, nothing to note that would explain the above.

Thanks for any thoughts or comments.