I've installed WordPress on a new server, most things work just fine, but in too many cases, I get a "You do not have sufficient permissions to access this page" error, which shows up when working with some of the plugins I have installed (but not in others), as well as with my theme's Options page (theme is Press75's On Demand).
The fun bit is that usually - stuff does get changed as requested, its just that WordPress seems unable to reload the page.
I turned off all my plugins, and reverted to TwentyTen. Tried uploading a new header image, and once again - no sufficient permissions (uploading stuff via Media appears to work only in non-Flash mode, but at least that I can pin on the hosting company)
Any ideas what might be causing this mess?
is it likely at all that this is all the hosting's fault, as a result of some server mode?