I've got a similar problem. I am VERY frustrated, as I use Oilpaint for my work. I have posted on several Forumsstarting 4 months ago, talked to Adobe (who gives no support for this) and have had no help.
I have been through 4 computers, my 5th is on the way .... several cameras and memory cards. Only one out of 4 computers has no iisue (my wife's). The problem seemed to be gone, when I bought my 4th computer .... then I bought another camera - now it's back!!! So, my conclusion is, that this issue has something to do with how information is written onto a memory card. Maybe some computers "pick up" on some little thing and get confused - I don't know. Again, only my laptop works fine, even with the new camera.
Try what I did, use another computer - until you find one that works ... friends, family...etc. Also, I just found out, that the only way to make Pixelbender work when it does not, is to turn off GPU ... although that slows the process down a lot.
If my new laptop does not work with my new camera, I'll get another camera and try again .....
My gear: 2008 imac, 2010 MBPro 13", 2011 mac Mini Server (since returned), 2011 Mac Mini i7/2.7 (selling), 2011 MBPro 17" (in the mail)