Hello !!

I'm sure this is some stupid thing, but it is really getting me annoyed. 

When I zoom in/out with the mouse wheel, as always so far now, it happens that since I installed SW 2013, small square pop-up, and it seems as it zoom just happen inside that small box. Then, suddenly the whole part update to the zoom/rotation done in the meanwhile.

I assume it must be something from  the news functions of SW2013, but I cannot find it in the pdf file 2013 "What's new".....

Please, does anybody know what the hell is this ???   

Attached a snapshot, for you to see..

Thank you in advance !!!