Yep, that's it!
Thanks, Willy

Sounds like this: http://www.mediamonkey.com/forum/viewtopic.php?f=12&t=61907&start=15#p420761

1 Start by clicking on the Windows Start Menu.
2 Now, type “Autoplay” in the search box then hit your Enter key.
3 Scroll down through the list until you find your iPod name.
4 Click on the drop-down box and select “Take No Action” option.
5 Click the Save button

Each time I connect my iphone to my PC, MM5 starts.

I think I have switched this on accidentaly, but I don't know how to switch it off.

The relevant options in MM5 on scanning and syncing are all unchecked.

Any ideas what I could do?