Hi!
I’m using blender 2.31a and I just experienced a very strange bug: I had several subsurfed meshes and when I launched a render, suddenly all their position were reset to the origin… as if I did an ALT-G for all of them! Then I tried to open the file I just saved before my render, but this file was “corrupted” too, all the objects were placed at the origin too! It seems that blender has a bug and sometimes doesn’t save the location…
Is this a known problem, or is it a new bug? What should I do?
edit
Okok, I’m very stupid and apologize to those who read my useless post…
The reason of the strange behavior I had was that all my objects had a loc ipo! Thus, at each refresh of the current frame, objects went back to the place it are told to by the ipo.
I really don’t know how and when I created this ipo without realizing it. It was probably my pet that decided to make a litte walk on my keyboard… That’s an easy solution that allows me to tell that it’s not my fault! 
Ok and if you’re still reading this post, it’s now time for you to leave, you loose your time! Go here!
Gabriel