Now that we have an AJAX page loading mechanism I do not see any need for using the jQuery UI dialog for editing privileges in the Users page.
A lengthy page is loaded into the dialog and it is the most user unfriendly way to edit user privileges.
It would be better to get this into the V4.0 release as this kind of change would not get into a bug fix release. Otherwise this will have to wait till V4.1
do you believe this to be complex to achieve?
If I understand you correctly, it's the length of the page that bothers you (from a user's perspective) more than using jQuery UI dialog?
Yes, its the length of the page and having to deal with this lengthy page inside a small dialog. I'll have a look at this today.
This bug was fixed in repository and will be part of a future release; thanks for reporting.