Its been a while since I last posted on here but been busy as they say.

I was just in the US on business and decided to purchase a laptop because of the excellent £ to $ rate we have. It is a Toshiba A215-S7422 with AMD Turion 64 X2 processor. It came as standard with 1gb of RAM in 2 x 512mb DDR2 PC2-5300. I also purchased 2 sticks of 1GB PNY PC2-5300 with it to replace the 512 Sodimm's. The problem is that when I put the 1gb modules in the laptop will post but Vista (home premium) will not boot. I checked the bios and it recognises the 2gb of Ram. I tried the modules in different slots and found that in slot 1 vista will not boot but if I put one in slot 2 with a 512 in slot 1 then vista will boot. both PNY modules work fine in slot 2. I am at a loss as to why this is? I am pretty sure the ram is compatible with the machine especially as it posts fine.

any suggestions, I've done some searches on google and see similar issues around but generally the laptops have been older toshiba models - if anyone can help I would greatly appreciate it!

cheers