Sorry people, but not resolved after all...
Today, Synamptic reported a broken package. When trying to repair it and downloading the app/file, another RMPDB error was reported.
Trying to do another rpm --rebuilddb gave a lot of error, first line a general one, then a lot of lines about specific applications (numbered).
I shall try to post the errors as I can. Problem is, as soon as I do the above, apps starts crashing radomly (or rather, so far, firefox did when trying to post). Hence, look out for my next post, hopefully with the specific errors.
Living without Synaptic? Not an option, me thinks, so please see if you can help this poor sod!