[support] can't reorder blocks after upgrade from 5 to 6

[J-P Stacey]

Hi,

> I recently upgraded from Drupal 5.12 to 6.6 and now I'm unable to  
> rearrange block order. I click and drag blocks to where I want them,  
> and as soon as I save it reverts back to the way it was. 

We've had some problems with the themes not being explicitly enabled on 
(among others) D5->D6 sites: when you go into themes, the radio button 
for the current one is selected, but none of the checkboxes are! 
However, this gives us a weird perms error on the Blocks page, rather 
than simply failing silently. But check the theme you want to use is 
definitely enabled.

Cheers,
J-P