What is really fasinating me right now (can't wait to get home from work), is the FOLDER named ver.req. I wish I had my camera here at work so I could test that right now.
I find that your problem appears to be unique in that I've never read of anyone, on any camera, on this forum ever having a problem getting the FILE ver.req to work. I understand that Canon built that functionality into the camera to identify the firmware version of the camera. I just cannot understand why your camera would behave any different? Does your camera have any strange markings on it, maybe it came from "The Twillight Zone"?
On a serious note, does your camera work properly without CHDK or SDM? Have you noticed anything strange or something mis-behaving on the camera itself. I guess I'm trying to rule out the possibility that the camera has hardware issues.
How long have you owned this camera, and how familiar are you with its features and functionality? Has it been dropped or bumped onto a hard surface. These cameras are pretty rugged but no electronic device like to be hit hard. My Son had a Sony Playstation 3 that was dropped 2 inches onto carpet, yes I said two inches, and never worked again.
One and one half years ago, I personally went through 4 Canon A590IS camera's before I returned it back to the store for a refund. Those camera's seemed to be very sensitive to having the lens bumped. Once the len got bumped it would get a "Lens Error" and would not go away. That's why I bought the A570IS's for my stereo setup.
Gregg