moving from 6.3.2 to 6.5

Hi

I have a relatively large application developed with php and postgres
using pg 6.3.2. I read the changelog for v.6.5 and i got a little bit
scared, but maybe i understood things in the wrong way.

In this application every "race condition" is placed in a begin->end
block and most of them even have lock's before they're needed just mo
make sure. If I upgrade postgres to 6.5 is there any danger that with
the new locking mechanism my app's database starts getting corrupted or
start's giving out the wrong type of information?

Thanks
-- 
        Mario Filipe 
        mjnf@uevora.pt
        http://neptuno.sc.uevora.pt/~mjnf