Let's see the code you're using to call into PDO, John; there's not much time before we release, and without your cooperation, the problems you're seeing won't get addressed.
I'll speculate that John's ADOdb snippet:
<?php $rs = $db->Execute("select * from table where a=? and b=?",array('a'=>1,'b'=>2)); ?>
is trying to bind 'a' and 'b' by parameter names, but the parameters in his query are identified only by their positions (using question marks). I wonder how that is supposed to work? Maybe he should try this:
<?php $rs = $db->Execute("select * from table where a=:a and b=:b",array('a'=>1,'b'=>2)); ?>
It's also worth noting (again) that PDOStatement::getColumnMeta is intentionally unimplemented on this first PDO release, hence its experimental status; in other words, don't use it. Most people don't need this kind of feature anyway.