[Xymon] Apache RRD - data not updated (NaN)

I am trying to get Apache RRD graphing work i xymon 4.3.0, but it looks like apache.rrd is not updated with data. I have verified that example.com/server-status?auto <http://example.com/server-status?auto> returns info, but according to "rrddump dump apache.rrd", only values I can see are NaN.

Does it return the *right* data ? You must have the "ExtendedStatus On" setting, or this URL will return data but not the right data.

Regards, Henrik