Emacs recentres point in buffer if it is moved anywhere -- annoying!

[purpleblues13]

Hi,

I have Emacs 24.4, running on OS X Mavericks.

I am encountering a very annoying problem which is that Emacs automatically 
recentres the point after every single movement. The is a small delay (ranges 
from about 0.5 secs to 3 secs), and then it jumps, just as if I had pressed 
C-l. I cannot find anything about this through google searches; no variables or 
minor modes, etc.

Weirdly, it usually doesn't happen. I can have Emacs open for ages without this 
annoying behaviour, then suddenly it just starts happening. I have no idea why. 
I have tried to restart and isolate all the commands I am entering, but I have 
not been able to work out what could possibly be causing it.

I can provide my init.el if necessary.

Many thanks,
David.