I published the app with IAP and when adding the file the website said: in-app purchases are not supported by pre-Belle phones (or something to that effect), would you like me to automatically remove all incompatible phones from your distribution? Note that the distribution list for my app wasn't actually changed.

The IAP webpage ( http://www.developer.nokia.com/Distr...pp_purchasing/ ) says this:
Qt: The Qt API for in-app purchasing is supported by Symbian^3 and later smartphones.

What I would like to know is - Are all Symbian^3 and later phones able to do in-app purchases?
Should I also publish a paid-for version for older firmware versions that aren't able to do in-app purchases?