semantics: Pahaana vs. pahaa.na

A problem that has only arisen because of my work with the Abhidhanappadipika:

Is the meaning of pahaa.na (retroflex .n) identical to pahaana (dental
n) or does it instead relate to the active/transitive meaning of the
root, viz., to beat, strike or defeat?

I have checked my available sources, but the issue is just slippery
enough that it's difficult to infer anything definite from them (i.e.,
I could easily fool myself into thinking that the dental-n meaning is
correct for the retroflex in any given instance).

p.s. --I'm sorry to report that there are significant differences
between the two Sinhalese editions of the Abhidhanappadipika that I
now use --most obviously, the total number of verses is inconsistent.
I did not expect this to be the case, given that the text has been
through so many dozens of editions on the island, and is heavily used
--if not heavily studied.

I don't have a Burmese edition of the text --Jim, when we met in
Toronto, didn't we vaguely plan for you to send me a Xerox copy of
that here in Lao?

E.M.