From the Canon support website:
QUOTE
Only 3" (8cm) in diameter, the DC40's DVD -R/-RW discs are compatible with most DVD players and can store up to 30 minutes of video in standard mode and 60 minutes of video in long play mode
It records to the 8cm DVDs which IS a miniDVD camcorder. Meaning it doesn't record to the large ones.
Make sure the disc is finalized and put it in your computer's DVD burner or reader. Run Media Import. Click on the VIDEO TAB. The drive should show up in the drop down list. Select it and the movies will show up below that. Select the ones you want and click CAPTURE NOW.
You can also access Media Import from inside Videowave and MyDVD from the FILE menu. Just select CAPTURE/IMPORT.