Help with stored procs Please !

I have a program which uses stored proces extensively.
It has work for a couple of years but I have upgraded from IBobjects
3.6 to 4.?
AND I have gone from Delpi4 to D6 AND from interbase 5.5 to firebird.
Yes I know one should make one change at a time !!

However I now get 'parameter mismatch' when almost every stored
program is called.
I did use 'now' within IB and thought that was the cause. So took it
out. Still the same effect.

I use autoparameters for the stored proc which worked fine. But on
close examination I see that I have parameters in my stored procs
which are not fields of the relation to which it refers.

This used not to matter. I assume the autoparams were obtained from
the stored proc. But now it looks as though they are obtained from
the relation ??

Anyway it looks as though I shall have to tell each stored proc its
'ParamNames'. In which case do I have to precede them with '?' or ':'
or nothing.
e.g. storedproc1.paranames.add('surname,firstname,...');
or storedproc1.paranames.add(':surname,:firstname,... ');