Plugins neither activate or deactivate 2.3.beta1

Hi – plugin installs seemed to be failing here and there on 2.3-alpha, updated to 2.3-beta1 and have a new issue – clicking on Activate brings a page with the message:

Are you sure you want to activate this plugin: “”?

No Yes

Both ‘no’ and ‘yes’ have ?action=activate, clicking on either gives the “plugin activated” message but in fact it hasn’t.. Deactivating has the same issue – success message, but no change.

Any clues?

Thanks in advance!