DDR and SDRAM on the same board. Good or bad idea?

I've got a ECS K7S5A. The board supports both DDR and SDRAM, it has two slots for each. You can use both types of RAM but can never have more than two SIMMS used at a time. So how odes this work? Would the board just use up the DDR first and then use the SD second? So far I've just got 256mb SDRAM, but I'm planning on getting 256mb of DDR sooner or later. When I do should I just remove the SD or leave it in? I'll leave it in as long as it's not going to be slowing things down. I don't often have much of a need for more than 256mb's, but it'd be nice to have for the occasional time I do.

Taken from the product info page of manufactuer:

2 DDR DIMM sockets and 2 DIMM sockets support (can not be used simultaneously)

This means that it is a VERY bad idea to use DDR and SD at the same time. Probably wont post... but could ruin something... never know

Don't do it bro... not worth the risk

Ahh I just reread the manual on this. The wording they use can be easily mistaken:

"The mainboard has two 168-pin/184-pin DIMM sockets for SDRAM/DDR (Double Data Rat) SDRAM system memory modules. You must install at least one memory module in order to use the mainboard, and you can only use one of the both SDRAM and DDR SDRAM at the same time."

I read that as you can use one of each type.

From what I have read using SDRAM and DDRAM at the same time is not really posible with a normal chipset. You will be needing two memory controller to work with and array like that.

I would suggest that you forego such a complex array and use one or the other kind of memory. Besides the price of SDRAM is equal to the DDRAM nowadays, so buying SDRAM now is not a good investing.....