Firefox version 12 MAILTO from application not working

FF12 Applications using "MAILTO" Not Working My application is suppose to generate an email and put it in the OUTBOX. Version 12 of firefox stops with a Google search page with the MAILTO info in the search field. FF & TB are defaults This application has worked since about version 3 of FF. No other changes have been made to my two PC except loading version 12. Going back to version 11 and I have no problems. Doing a Google search I see that applications using "MAILTO" option is a big problem with Firefox version 12. See http://boardreader.com/thread/Firefox_and_Email_problem_9rc6X2c9zx.html plus other. I reload version 11 and I have no problems. I am using Avast AIS (includes malware/firewall) on one PC & MSN MSE on another (Both windows 7 64) (both have same problem)