Sometimes it helps to avoid this by checking 2 issues in your favourite modelling app:
1. is the floor made of very large polys and very small polys altogether (irregular distributed)?
2. is the shape of the floor polys somewhat extreme, like very long and small?
I tried to cut my floors into the most even spacing and shape possible (try to "tile" it if possible)and avoided very small angles to some success.
If possible construct your house the way that you can use floor segments in FPSCreator which saves you HOURS of fiddling to and fro. It requires some more planning ahead but collision with entities is a nasty business in FPSCreator.
If you want to "escape" while testing just try to crouch and walk that frees you from being stuck most of the time...
I am Jacks complete lack of surprise.