G is showing meta descriptions for my sites

Sites in the same server, may be any sever parameter?

[johnypalillo]

I have some well ranked sites that is changing since first days of September their description in the Google serps. Some of them reaching better positions and others going from 1st position to 298 ...

All of them are losing their old description, taken from the body text, and are showing the meta description. They have been migrated to a new server last June and the server had a 36 hours downtime from 3th to 4th of September. Some of them are dimanic sites but there are static html too.

May this be about any server parameter or hosting provider setting?

Thanks.