Are you running any plugins by chance? If you go to the options screen and then go to the General tab, there is a checkbox labeled, 'Enable Plugin Support'. Uncheck that box and restart VA. You can also click on, 'Plugin Manager' and see what all is loaded and try disabling individual plugins from there to see if the problem goes away.
If that does not solve the problem, please look in your VA installation folder and see if there is a VoiceAttackFault.txt file in there. If so, you can either post the contents of it here or send it to support@voiceattack.com.
Hope that helps!