AutoCAD Inventor :: Rendering Animations - 30 Seconds Limit?

I have prepared an animation which is 50 seconds long. Now, i just want to render that animation, but i couldn't.

The problem is that if i select "Entire Animation" option for the time range, and click the "Render" button, i obtain just an image rendered (1 frame) and if i try to write the time range manually by selecting the "Specified Time Range" option, i've realized that it is not allowed to specify a value greater than 30 secs. When i write "30.1" for instance, the forecolor of the input box turns red, and a message appears if i click the "Render" button, saying "Invalid Expression!"

"Help" says, "You can adjust any value in the input box.", however.

I've solved the problem by making two seperate animations and merging them by using an other video editing software, but i didn't satisfy the topic. Is there a limitation due to "something" or am i doing something wrong?