OT:[MAYA] interaction

[Gerbrand Nel]

I just want to check If this is a known issue, or if I'm hitting my head 
against my own stupidity.
I'm modelling something in Maya for the last 2 days (would have taken 3 
hours in soft, but hey, its a learning curve) ,
And every once in a while my interaction stops working. Like the "f" key 
no longer frames selection, or the modeling toolkit stops previewing 
edge-loops. F8 also stops doing what it should be doing.
When I save and restart, all is back to normal,
So is there some "mode" or "thing" I don't know about, or have you guys 
found it buggy too?
It's Maya 2014 sp2 30 day trail.
Thanks
G