Sony DSC-H50 Memory Card

[jasp]

Hi

Firstly,hi to everyone here as i've just signed up to this forum

The problem:

A couple of weeks ago i noticed a problem when shooting videos with the camera - when i play them back on the camera (or PC) theres a "chh" sound on the video which is heard every second...when i shoot video in medium quality mode the noise is heard every 2 seconds or so on the resulting .mpg file

Anyways i was trying to find the cause of this today when i thought i'd try using a different memory card (the one in the camera is a Sony Memory Stick Duo Mark 2) i put in an older Sony Memory Stick Duo card which isn't the Mark 2 variety and the noise is no longer an issue

So is it a case of the camera not liking Mark 2 Duo cards or is the card faulty (very unlikely and it is a genuine card btw!)

I also tried shooting a video without a memory card and also had no noise on the file

Any ideas anyone?