I upgraded. Does resubmitting my sitemap make me loose the URL's that were indexed?

I was running Sitemap 2.5 and in Google Webmaster Tools it was showing x,xxx URL's in the web index.

I upgraded to Sitemap 3.0 and resubmitted my sitemap to Google, and now it's showing 0 URL's in the web index.

Is there anything I should be worried about?

If I'm upgrading from 2.5 to 3.0, is it necessary to resubmit the sitemap or just leave it be so I dont loose what was shown as being in the web index?

It takes abit of time your sitemap indexed urls appear in google webmaster tools. You should wait and see.

When you resubmit a sitemap you simply says google i have new urls for you. It does not directly effect the indexed pages. It takes longer time for indexed pages to be cleaned or added.

You can check how are they by this specific search at google.com site:yourforumrootdomain.com it shows what's right now present inside of the google.com search database.

Thank you for your help.

If the problem continues, please let us know. I think you should start seeing results within 24 hours back in the webmaster tools.