not that I enjoy doing this, but that is advice fail. The mobo only has 2 DDR slots, so the OP would need to buy 2x1GB DDR memory, which would be pretty expensive nowadays, as DDR is regarded as "legacy" and commands something of a premium.
The other 2 slots are for SDR SDRAM, and the board cannot run both SDR and DDR memory simultaneously.
The board *should* accept pretty much any DDR memory, but it's only rated for DDR-200 / -266, so if you use anything faster (like, for instance, the DDR-333 you've got in there) it'll still only run @ 266. Frankly, if you've got 1GB of memory in a p4-based computer already, you're not likely to get much improvement from adding more memory, and what improvement you do get certainly won't merit the additional cost (e.g.
1GB DDR266 @ ebuyer: £33!). Why are thinking of a memory upgrade anyway? What are you having problems with?