Users Listing: Roles field set to "manager", can't change.

The first time I visited the Users page after installing the 2012-Jun-09 release I saw all my users listed. I noticed the field "Roles" could not be changed from "manager". Playing with it further I hit the Apply button and sure enough now the only user visible is the sites "manager" account. Of course, still being unable to change the Roles field I am then unable to clear this filter and view all my users again, navigating away and back doesn't clear it nor is there a clear button. Disabling the module gives the original view back but naturally leaves me back where I started.

I'm running...
core: 6.25
views: 6.x-2.16
VBO: 6.x-1.13
platform: Ubuntu 10.10
PHP: 5.3.2-1ubuntu4.17

Please let me know if you need any more info.

Cheers,

Roger

Also: I've reported this as being a problem with 6.x-1.x-dev however, my modules screen is showing 6.x-1.0-alpha1+1-dev. I initially copied the recommended release for D6 into my modules folder, then I noticed it was "alpha" with a couple of serious bugs so I replaced this folder with the latest "dev" at the time (2012-Jun-09) to see how things are going. I never enabled the alpha module though so it shouldn't have made any changes to the DB but thought I'd mention it as I'm a little confused by the naming convention being used here (almost certainly me being dozy!) just in case that indicates something else is wrong somewhere.