state field not required, even though set required,causing issues with tax rules

[goalex]

Greetings,

I have a tax rule setup for Washington state.  on my website, (as a customer) when I select "Seattle, Washington" for the state my address and then switch it to Singapore, the state "Washington" remains and I still get taxed for Washington state. 

And if a new customer registers and forgets to select the state (e.g. "please select" only) , the tax rule for Washington state is applied.


I have made the state field mandatory.  I tried different browsers and settings in joomla control panel (disable and enable jquery).  I also tried different template like beez2 - Default. 

The same issue happens.

Here is  my environment:

PHP Built On    Linux  2.6.32-042stab078.27 #1 SMP Mon Jul 1 20:48:07 MSK 2013 i686
Database Version    5.5.32-cll
Database Collation    utf8_general_ci
PHP Version    5.4.4
Web Server    Apache
WebServer to PHP Interface    cgi-fcgi
Joomla! Version    Joomla! 2.5.9 Stable [ Ember ] 4-February-2013 14:00 GMT
Joomla! Platform Version    Joomla Platform 11.4.0 Stable [ Brian Kernighan ] 03-Jan-2012 00:00 GMT
User Agent    Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.71 Safari/537.36
SEF is enabled
Virtuemart 2.0.18a

The following are all checked:

Activate Css Styles & Javascripts
Using the VirtueMart CSS   
Using the VirtueMart jQuery   
Using the product Scripts   
Using the Script ajax Countries / Regions   
Use external google jQuery library


I searched the forum but could not find articles specific or with solution to my issue.

Please help, any insight you provide would be greatly appreciated, and thanks!!