OK, I think you’re referring to the issue of non-slip timing. That’s a potential problem for people writing their own code but should not normally be a problem for standard builder experiments if they have a trial/epoch with pre-determined duration (which will show up as green on the Flow panel). This is explained in the final post (by me) in the thread you linked and also in the documentation:
http://www.psychopy.org/general/timing/nonSlipTiming.html
It looks like you aren’t getting fixed duration trials, which I’ll take up in that separate thread but as and when that works the cumulative delays will not be an issue for you