When I alter and re-submit a sitemap does GWTs immediately re-evaluate it or do I have to wait 'til GoogleBot crawls our site again?
I just re-submitted a problematic sitemap and it now displays the green tick next to it but does this really mean it is valid? I need to know is the problem really solved.
Google Webmaster Central says:
"Once you've reviewed your Sitemap and made any changes, save it and then resubmit it. It can take up to a day for Google to process the resubmitted Sitemap, so the warning status may continue to display until then."
I would use this to answer the question, but does this actually mean that my problem is gone? (Because the icon changes from a red X (error) to a green tick (valid)).
I'm not so sure.
I simply resubmitted one problematic sitemap without any changes and the icon changed.
On the details page of a problematic sitemap I re-submitted, the Downloaded date is today's that. Does this guarantee the error was fixed? Because the Downloaded date is today for both sitemaps I re-submitted (see edit #1)