There is a total break down between 2nd and 3rd edition bytecode for Symbian Series 60.
One easy solution would be to use Python for S60, but it will then be limited to S60 so forget UIQ.
I strongly recommend you guys to switch the mobile development to Mobile Java.
I love myself better the Symbian C++ application since they are faster than Java ones. But maintaining applications for Symbian 3rd edition in at the moment a royal pain in the ass. Making application to work on 2nd and 3rd edition is difficult and time consuming. The 3rd edition security introduced more work and you have to send your application to testing + pay to sign and distribute them. The new 3rd edition release will have the capabilities changed... And I skip the details
A good mobile Java application would be much more portable and would save you lots of development time.