double posts/requests to mysql corrupt cached table data

I posted an issue to the mysql dev forums last week with regards to an
issue we are encountering. The issue as we understood it last week
was simple...after some time (undetermined as of then) query results
from the web app (a PHP/MySQL/Javascript Ajax app.) would come back
all 'wonky.' Upon issuing a mysql-server restart the data would be
fine, and query results back to normal. This morning I figured out
how to replicate the issue. Issue a double request for the mysql
result set. Due to the "Ajaxy" nature of my web app it isn't the same
as a double HTTPRequest of POST, as it is requesting a result set back
from the database twice in a row before the response is collected.

We run Apache 2.2 on FreeBSD 6.1.x, I am currently running MySQL
5.0.x....given the fact that I can repeat and reproduce the problem by
either hitting my refresh button twice, or by hitting my javascript/
Ajax button twice before I get my first response....can anyone point me
in a direction to narrow down why my code might be doing this? I am
using PDO with prepared statements and MySQL stored procedures to
produce my result sets...all httpxmlrequests are handled by prototype.js
1.5.1.x If you asked me yesterday, I'd have said I wasn't doing any
thing that MySQL couldn't handle...but apparently that isn't the case...