Web Monkey:I'd bet that if you asked Aqualung nicely they would repair/replace/upgrade your BC to the current style, which uses some type of positive locking mechanism (can't tell exactly from their website).
It's bad for business when your products cause your customers have repeated runaway ascents.
I would probably try and do this too. Aqualung has made SureLock (a quicklease system) standard for their weight integrated BC.
One of the instructor I know had the older version of the ProQD which uses velcro for securing the weight pouches, he had lost a weight pouch. I have got a SeaQuest ProQD+ which comes with the SureLock system. Never had problems on weight falling out.