Photo Booth 2.0.3 is not working properly

I have a mac book and am operating with Mac OSX 10.5.8. Amongst other problems I have been having with my computer one that really ticks me off is Photo Booth. I like having the option of recording video which the program does do however, it only records about 40 seconds of footage. I've also noticed the problem is intermittent, sometimes it records a longer video, sometimes it will cut me off 15 seconds after recording. When the computer was new the program obviously worked fine. I just started noticing the problem about 6 months ago. I am not all that Mac savvy but I do know more than the average user. If anyone can please tell me how to fix the problem so I can record as long of a video as i want, it would be greatly appreciated. Thank you.

Bryan