Problem with loading document

 
After switching from the demo to my own licensed SDL Trados I have had problems with loading files. When I have selected the languages the OK button do not respond and nothing happens. I have reinstalled the program once and it worked for a while and the same happened when I repaired the program, but only for a short time. Now I have tried to repair again with no luck. I could of course try to reload again but I am not happy having to reload the program tvice a week.
I hope someone can help me.
Best wishes, Steinunn