Big variation (1-7) of pagerank across datacenters

I've been looking at one of my domain names in the Pagerank Checker at www.iwebtool.com and it gives my Google pagerank as '1' on most of the datacenters, all except for 66.249.81.* which lists it as '7'. Why is there such a big variation, and which is right?

 

Iwebtool have some errors in their Logarithms ..i Get Pr7 also for all my sites .
technical problem it seems

 

Thanks. That's a pity ;-)

 

I saw the same thing for my web sites. But when I check the same datacenters with my tool it gives the right pagerank. So there is a problem in iwebtool.com