You might want to try to retest the new version after you've experimented with new antenna positions or channels - how far apart are your routers from each other? Is this a 2.4 or 5GHz bridge?
Thanks for the added info.
The are 3 physical floors between two routers. On a 2.4ghz band. I've tested and tried everything there is to test and try.
It works in the mean time, so that's all I care about.