reconcile reset? and related issues

[Maris]

I've got probably a bit in a mess while doing some reconciliation actions.  
Anyway, after some pause in doing a gnucash job and updating from 2.2.9 to  
2.4.5, I've learned more about this fine feature. However upon an  
A/P-account (just not on the complementary A/R-account there appears to be  
a whole bunch of 2010 entries apparently marked as reconciled (no visible  
entries), while the right side shows unticked entries that I cannot match  
with left side entries.

Question: I'd like to reset the reconciliation for any particular account,  
so that I can start reconcile that account from scratch again. Anyway, it  
is not possible to alter the flags in the account register. Other account  
registers have an R column, but A/P & A/R don't. Instead, they have a  
"type" flag (with ?, I and P) modi, where I do not find infos about it (I  
found that I makes entries readonly, and that it cannot return to ? again).

Any help is highly appreciated, since I'm quite in a :( mood after  
investigating it extensively...

-Rob