MATLAB: Matlab suddenly crashes/exits with no error msg.

crashjavaMATLABmex

I have recently had a problem with Matlab suddenly exiting. I have not identified a spesific action that will make it close but here are two that i can remember:
– ctr-v , pasting something
– edit ***.c , creating a new .c file using edit command
Please note that i have not reproduced this enough to be sure that it is related.
Also after the crash, matlab will not start again unless i reboot the machine.
Me myself i have two theories :
1) Could it be related to Java? It seem to happen more when I get the "A new java version is avalable popup". (I often deny this update as I figure, meh ill update it later ),
2) I have had some mex related crashes due to memory etc. could there be a corrupt file somewhere?
Have anyone experienced something similar? (I use matlab 2013a on windows 7 ) Thx in Advance!