When you changed out your motherboard, did you update your operating system at the same time? If so, you might have rouble with CS5 anyway. But Adobe no longer supports that version of Photoshop or Camera raw, so you have to go through someone who actually has a copy of that old camera raw out there for download. I found the one here on the link below. I do not know how safe that download would be, if it would work or not or anything else about it, but it's the only one I could find with that version of Camera Raw.
Direct from adobe:
Other adobe updates:
Thats true CS5 comes with Camera Raw... Its been long time i didnt install everything i forgot!
Thanks for the links its usefull for the updates!