SharePoint 2010: WebPartZone not rendered when i'm not signed in

I have a custom WebPart on my welcome pa开发者_JAVA百科ge in SharePoint 2010. When I open the page without signing on, the whole WebPartZone remains unrendered (according to the responded html). When signed in, my WebPart works perfectly. Afaik, my WebPart does not require any special permission, it just pulls content from some lists on the same SharePoint site.

Any ideas?

thx, M

Some of the Page layouts are defined in such a way that the Web Part Zones are removed if they are empty:

<td id="_invisibleIfEmpty" name="_invisibleIfEmpty" colspan="3" valign="top">

Is your page published? If the Web Part is only in the draft version of the page, the Web Part Zone could still be empty (and then removed) in the currently published version.