Everybody knows that Google has changed it's PR calculating URL a week ago. So all 3rd-party scripts now unable to calculate and display it.
There is a simple solution for those who are using SeoQuake toolbar for FireFox:
1) Go to SeoQuake Options-Preferences
2) Select "Google pagerank" line and click "Edit"
3) Put the following text into the "Edit parameter" box:
Code:
[NAME]=Google pagerank
[TITLE]=PR
[URL_R]=http://toolbarqueries.google.com/tbr?client=navclient-auto&ch={gchecksum}&features=Rank&q=info:{url|encode}
[REGEXP]=Rank_.*?:.*?:(\d+)
4) Save changes.
Done!