Tell us about your temperatures and weather through that time period?
Too hot weather can stop tomato plants from producing or sometimes if the nights are not cooling off enough compared to the daytime temps the plants might not produce well. These are common problems with tomatoes in summer where I live.
How bout pollination? Flowers that don't get pollinated will drop off without producing fruit.
Are you sure the blossoms are just dropping off? Make sure there are not tiny little fruit forming that you just don't notice right away, I sometimes have to wait some days to be able to tell if where that flower dropped off is forming fruit or not.
Other things I'm not so sure of might have to do with sudden changes in water chemistry or pH affecting the plants and if you don't have enough potassium available in the system the plants will not produce fruit as well.
My computer was down for a few days and now I'm back on track, plus getting ready for Orlando.
The temperature has really been extreme for both day and night. I didn't notice any fruit at all, so it seem to really be teh temperature. I'll keep you posted...