hi Dileep,
i think i know the solution coz i had same problem when i had borrowed my friends Canon Camcoder sometime back ...
dont worry its not a problem with your DVD RW drive nor with Camcoder

,
once finished with your recording/shooting you MUST Finalize the DVD in the Camcoder (which hardly takes few minutes) else it won't play on your DVD RW drive or DVD player and may show you 0 byte data on PC since it cant recognize the video format. ... Simple isnt it...
Steps to Finalize the DVD will be surely available in the Camcoder Manual