steppinthrax,
It might make a difference HOW you add another GB of RAM.
If your current 1GB is on just 1 stick, there's no issue, just add another like it.
If your 1GB is made up of 2 X 512, then the question is: whether to add another 2 X 512 sticks bringing your total to 4 sticks, or to instead replace them with 2 X 1024 sticks.
For the (aging socket 939) motherboard I have, OCZ warned that it's really better to not fill all 4 memory slots.
OCZ said that to go up from 1GB to 2GB, it's better (for this 939 mobo) to replace the 2 X 512 MB sticks with 2 X 1024 MB sticks instead. Reason: so only 2 of its 4 RAM slots will be occupied.
QUOTE
Your best option is a 2GB DDR1 kit by itself. At times the memory controller of the 939 processor can have problems with four sticks of memory. END QUOTE
by "Praz" on The Official OCZ Support Forum
Please understand, I'm not making a recommendation to do the 2 X 1024 route, but I'm just bringing it up as a possible issue (or non-issue) you might spend a few minutes looking into.
edit: added quote notation