Fluid simulation errors

I have been having a problem baking fluids for awhile now that persists thorugh 3 different version, so i am probably doing something wrong. Ok, so i can bake a fluid sim, and everything is just fine usually. but, when I change something and rebake it, I always end up with errors. Sometimes the fluid decides to spread along the wall of domain filling every side and causing massive lag which crashes blender, and sometimes to just renders the basically a shell of the first frame and then it keeps that for all 250 frames. This happens in 2.49, 2.54, and 2.57. Why? If this is an uncommon problem I can upload pictures.