Advetising

Hi can you help i added some html code for advertising on my site they all came up working fine.I went to my site today and they have gone and not showing up,i deleted the code and re pasted it back and saved but the ads are still missing ???.This has only just happend they have been there for about a week but they have just gone even though the code is there can anyone help or any ideas please thanks.

I don't think this is a bug, it should be some thing with your database or some one elase is changing the advertuisement (you may need to change your admin password).