Thx for the reply Ovid.
The DBI object is instantiated like so:
my $dbh = DBI->connect($dsn, $user, $password,{'RaiseError' => 1});
I can't $sth->execute( @key ); as I am using elements 1 - 6 and not 0 or >6 . Element zero is the word radio to distinguish the radio values on which I am acting from the other params.
The real puzzler here is that the data is the same for each branch and if we are Adding we move the row then delete if we are just Deeting we execute code identical to that which deletes the rows successfully if Add was chosen.

Anyway I can't see that the split is at fault in one branch and not the other. Oh and yes I am running under strict and -w. Maybe I should create a trash table and just move the rows there and then delete the from $holding_table thereby replicating the success I have when Adding. lol..sigh.
Thx for looking at it!
jg