Whatever you have it is listed in Apple System Profiler.
Get an ASP report and go to the USB section.
For my 2300 I get :

USB Device:
+----------------------------------------------------------------------+
| |
| Product ID : 16385 ($4001) |
| Vendor ID : 1670 |
| Device Speed : Full |
| Power (mA) : 100 |
| |
+----------------------------------------------------------------------+


And verify that your canon is in PTP mode. Recent Canons have two modes : one incompatible and one compatible ;)

---
--
Thomas Deniau

I have 500mA for my Dimage 2300, is it the problem ?

The dimage 2300 takes a lot of juice.

Not having seen this tip in time, my solution to this same problem was to go out and buy a USB compactFlash card reader (mine is Lexar - i'm told another in the same price range that works is SanDisk but i didn't try it).

The Card Reader cost 40 CDN (27 US) dollars and requires no extra power from a/c or battery...or wear and tear on the camera. Were it not for how much juice the minolta sucks back i might try this tip out, but without an a/c adapter it is hardly worth it.