Hard crashes


I have a 2006 iMac with Intel processor and 2 GB RAM running Leopard.

First problem - Hard crashes during Mail (rarely), importing video to iMovie from Canon HV20 video camera (almost always), and when rendering a DVD in iDVD (almost always). Message on log is "This call is deprecated and should not be called any more."

Second problem - Won't burn audio CD's or DVD's. Used to be fine. Now says "laser can't calibrate to the media" or similar. Have tried assortment of discs.

HELP! I mainly use the computer for iTunes, email, and making fun movies to send to relatives or for school projects.

Thank you.