There was an issue identified in vBulletin 4.1.0 and 4.1.0 PL1 that  may potentially break a number of 3rd party plugins and modifications.
Please note, this issue does not affect the core vBulletin product, but  changes that were made to the core vBulletin product may potentially  break 3rd party plugins and modifications. 
As part of our inclusion of the mobile APIÂ’s, the vBulletin templates  were re-factored in how they are rendered to support the API. 
The $vbulletin variable was placed so that it was not part of the  eval process, and subsequently out of scope for the templates of 3rd  party plugins and modifications templates.
Here is an example template conditional that would be affected:
Code:
in group 5, 6 or 7
We have...