I'm experiencing a puzzling problem that I've never come across before and I therefore thought that I would post and see if anyone else has seen and hopefully solved it.
The problem is that we are unable to preview or edit any other version than the published one. You can select a new version and this version is highlighted as soon as you stay on the versions tab. Selecting the Preview or Edit tab switches back to the Published version. This also affect the Save and View button as this also switches directly to the published version, practically disabling the whole 'Ready for publish' functionality completely.
For reference we are using CMS 6R2 with Find, ImageVault, Mail, BVNetworks 404Handler, EPiServer.CdnModule, Cassette.
I have had this exact same issue, but I can't remember the reason for it (it was a while ago). I'm pretty sure it had something to do with a custom property that posted back incorrectly.
Thanks for the reply Deane, I've been looking at custom properties, but this also happens on pages that only contains standard properties which made me rule this out.
Also seems like it is affecting the page tree tracking and the navigation to edit pages from within the preview window.
The hunt continues...
Finally solved it! Eventually found that a module was accessing the CurrentPageLink property in the PreInit page event handler, making it cache a value without work id before the hidden input field that contains the full page link with work id is instanciated.
Took some serious debugging to figure that out.