So sorry to hear you're still going through what it feels endless process with allocations. I have followed your past threads and fully understand how exhausting the waiting game and uncertinity are.
Just in case you have not seen the link in below post, it may be useful to give you an idea which schools may be available in Bucks:viewtopic.php?f=12&t=19840
Although the data there is just a snapshot from late Feb 2011 you may still be able to find out from Admissions as to what the current state is and update waiting lists choices accordingly for next round. Good luck with your pursuit!