hi all! i'm running a mac pro 3.1 (early 2008). never had any trouble with it until recently. after i dusted the machine it wouldn't boot anymore. the techies told me that all ram modules (original 4x1gb) are ok, the two ram risers as well (checked all that myself as well) and concluded that my logic board has a problem with the upper ram riser slot. i'm not running any ram intensive a/v programs. i simply want to have a fast desktop for my work related stuff. so at first i was pissed, it's some problem after all, but it didn't seem thaaat much of a difference being down to half my ram. but all this somehow coincided with my idea of several upgrades i planned (have an ssd, a better and less noisy graphics card) and ram was in my list as well... i can't afford 900 $ for a new logic board. some friends too told me that my desktop isn't worth it (whatever...). so yesterday i just thought i'd try what those techies told me i could not do: i put the rest of my ram into my remaining ram riser - and lo and behold, system profiler shows me i have 4x1gb ram in one ram riser! (according to mac manuals for the mp 3.1 ram shouldn't or cannot installed in the way i did...) do i take any risks in doing so? does anyone have an idea? had had a similar situation problem? looked quite some time on the net for similar cases... so i'd be really grateful for any hints and experiences!