I have N70 music edition....
When i convert video files on my pc to mobile format (mp4,3gp nd rm) , and then transfer them to my N70 , and when i try to play these files the screen shows up ---> Unable to play media clip .

Is there a problem with my N70 or is it a problem with the converter ?
Please help me out.....:con?

The problem is probably what format/codecs/resolution/bitrade you convert the video files to.

Check this table for what the N70 supports:
http://www.forum.nokia.com/main/resources/technologies/audiovideo/av_features/FN_vid_table.html