code for two ad units but only one showing for months

remove the first ads code and the second shows fine

[proper_bo]

I have two ad units coded into every page of my site.
The first is built into the content and the second is built into the menu. I have checked the code multiple times and know it is correct.

The menu ad code always shows.

If the content reaches X words long then the second ad code shows (but comes first in the html).

If the content ad code is live on the page then ads will be shown in this unit. If I refresh the page several different lots of ads will appear. If I use the preview tool there is no shortage of ads being shown.

The problem is that if the content ad shows, the menu ad disappears.

It has been this way for a couple of months since I launched the site. I have never seen both ads show together.

On a couple of sites I have seen people talking about google limiting ads to one unit on their pages. Does anyone have experience of this? What about on a new site like mine?

Thank you.

[proper_bo]

I switched a link unit for an ad unit and puff, both adverts now appear. Not ideal but it will do for now.