You may be limited by the resources on your machine. I would suspect that in most cases there would be some type of error message associated with this such as an 'out of memory error'. I have received such messages in the past and have had to either free resources on my system or get more RAM.

Try the solution presented by davorg. If you receive an error message, then you probably will have a hint at what's happening.

I hope this helps....

Mick