I never knew that it was a 4.0 update , the latest that i know was the 2.8 but i find out the 4.0 truth Toshiba in the US . Here's the link for it .
http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/modelContent.jsp?ct=DL&os=&category=&moid=2809950&rpn=undefined&modelFilter=HD-A3&selCategory=2797338&selFamily=2805945
http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/modelContent.jsp?ct=DL&os=&category=&moid=2809950&rpn=undefined&modelFilter=HD-A3&selCategory=2797338&selFamily=2805945