I am sorry, that particular stick will not work. Put it another way, you will only see 256MB, instead of 512MB. The IO cannot use RAM chips with densities over 128Mb. 128Mb is OK (notice "b" and "B" here). So, for 128MB your SODIMM module needs to have at least 8 chips on it, for 256MB 16, for 512MB 32 chips. I actually doubt that you can find any 512MB SODIMMs for the IO.
On the other hand, there is a great number of 256MB modules on eBay which will work in the IO. I already gave this same answer to another thread two months ago, but nobody seems to have read it... So, here it is again.
I bought a 256MB SODIMM on eBay way back in the summer. It was dirt cheap at that time. ;)
It is a low profile, 16-chip, CAS-2 PC100 SODIMM. Here is an image of my SODIMM. It is double-sided, i.e. the other side has 8 chips on it as well. It works flawlessly with CL2 at 110MHz, I have been using it at that speed since I bought it. You can find many of these modules up for auction on eBay, just keep watching this page and you will have your RAM in no time. Look for items with no reserve price.
One to watch would be this. It looks like mine... In any case, do make sure that the module has 16 chips.
That's all about it. Good luck!