How do I find Studio 1558 compatible RAM?

Hi,

I recently tried to expand the RAM on my Studio 1558 to 8GB by plugging in 2 Corsair 4GB sticks, which their website claimed were compatible. However, Windows refuses to boot with this (continuous reboot loop, and some page-related BSOD if I use only one stick). A quick search on the Internet shows that many people have had similar problems finding compatible RAM for this laptop.

I tried to find a list of compatible RAM from the Dell website, but looking at the memory configurator tool it only shows me one type of RAM for the Studio 1558, which is a 2GB module (and sold out as well). The 1558 can support 8GB, so the question is: how can I find out which 4GB modules to get without buying them all and just trying?

Any help is much appreciated!

Han.