08-29-2012 07:38 AM
Well, that proved even more complicated than I expected but I seem to have achieved the desired result eventually.
First point to note, deleting the BTYahoo email account did not remove the contact or calendar data (although it did remove the Service Books).
Secondly, adding a Gmail account to the BlackBerry is not as simple as you might think and I had to go to m.google.com from the BlackBerry and download a special Sync app in order to sync the Calendar and Contacts data.
Having done that though, all seems to be working.
Once again, thank you for your help which got me on the right path.