my site is showing ad duplicates

is this normal?

[dagford]

Can someone please tell me if it is common to see the same ad two or three times on the same page.

I only have three ads per page, and I am frequently seeing the same ad appear three times. Not good!

Another problem is that occasionaly one fails to appear at all.

I have placed the ads inside a colored DIV and there is also a border around each (not the Google borders but my own CSS). Could this affect things?

Cheers

[ArtistMike]

Not normal.

[humblebeginnings]

I am seeing this too lately.
For example: 2 ad-blocks on one page showing exactly the same ads at the same time.

[theRealairness]

I sometimes see the same text on the link, but the link points to a different website.