I have used the plugin on 1.6 and it works fine.
When i try using jquery 1.9.1 i get an error:
Uncaught TypeError: Cannot read property 'msie' of undefined
On loading the 'blockui.js'
I cant find any reference on this, is it possible that blockui is not supported on jquery 1.9.1?
You should either include the jQuery migrate plugin, update the plugin to not use $.browser, or don't upgrade jQuery past 1.8.3.
$.browser was removed in version 1.9
From jQuery's Documentation:
Description: Contains flags for the useragent, read from navigator.userAgent. This property was removed in jQuery 1.9 and is available only through the jQuery.migrate plugin. Please try to use feature detection instead.