The issue seems to be with Bitinstant, not Zipzap.   Zip Zap will typically show the funds as processed, and then a hour or two... and sometimes SEVERAL days later Seth, Rachel, Charlie, etc. will push the payment through.   Seems like it should be more efficient.... hopefully they will tighten up their ship and get it together eventually.   

The musical chairs thing they do with disappearing countries and payment avenues (Bitcoin address today, not tomorrow... BTC-E disappearing... ) doesn't really inspire confidence either. 

That said, they haven't lost any of my funds yet.    (props please if they use this as their new slogan)