Question: I need to record a demo of our application. Can anyone recommend a good screen recorder?

I have tried CamStudio, but it's throwing errors. Any other good free software I should try?

Answer: 
Camtasia studio does a great job.  

In the case the app is cross-platform (java, web-based) you can ask a pal with a Mac to use Screenium, Snapz Pro or ScreenFlow.
There are lots of screen recording tools around, both free and professional ones, but I haven’t seen anything like ScreenToaster before. It's very nice applications for screen recording.