Navigation Problems

Sometimes I can’t seem to navigate all of a sudden. NUMPAD 0 seems to randomly jump me to an odd angle with an elongated camera view. NUMPAD Dot jumps me to an odd angle off of my 3D cursor, and moving with MMB seems to revolve me around some unknown point far away.

What am I doing wrong and how can I fix it?

EDIT: Also, pressing NUMPAD 1,3 or 7 jump to random points at odd angles to the object I’m working on.

Numpad 0 toggles between current and view through the camera
Numpad . focuses the view onto the currently selected object
In User Preferences / Interface you can select ‘Rotate Around Selection’ which may give you beter control on MMB rotation

Thanks, that does seem to help.