Not that I car about PR but one of my sites was just listed in DMOZ and I was at a PR6 now its a PR4. I havent done anything different to it, except being listed there. Has it happened to anyone else? As for my PR I really dont care, I have a PR1 site that earns very well, better than even some of my PR5 sites. But I just thought it was wierd....
Have never seen it have a negative impact... so most likely the drop was caused by something else and just happened to coincide. Any number of other possible causes... some odd tweak in the google algorithm, server issues when a bot was trying to visit, who knows. PR optimization is a moving target.
DMOZ will boost your PR if anything so it must be something else that has affected your site. Google always f#ck around with their algorithms too which is tough.
Not that I car what you say either, but being listed on dmoz doesn't lower your pagerank. Letting your site sit and not doing anything else will though. Especially if you're just sitting there watching dmoz.