I didn't mean to imply that the camera model had any effect on the issue, but rather that Canon is possibly not offering the same version of DPP for all of its models. Knowing the model, anyone can look at the specific download page for it to see which version they're offering. If it's not the latest, try going to the SX1 IS download page and download the version I installed last night.
Edit: I just checked the 7D downloads and the same version is offered (3.12.41); here are details on the system requirements for it:
3. Target Applications (required for update)
Make sure that at least one of the following applications is installed.
- Digital Photo Professional
- RAW Image Task
If any of the above applications is not installed, prepare one of the following installation CD-ROMs.
- EOS DIGITAL Solution Disk v1 to v25.4
- DIGITAL CAMERA Solution Disk v2/32/32.1/38/38.1/38.2/39.1/53/54/71/72/73/74/96/97/99/100.1/101.1/122/123/124 /125/126/127
- Digital Photo Professional Disk v1 to v1.6