IE 8 and Mozilla Firefox 3.5.7 are getting crashed during the recording started

I have used beta version of Loadrunner 9.50 that directly download from HP site.but when i take the same to record my application, the browser (IE 8 and FF 3.5.7) got crashed so I can't go through there with LR.

I had tried to change the browser setting through VU gen->VUser-> Runtime settings->Browser Emulation->User Agent->Change->I tried to change the browser and verion but it is not only getting changed but also it displayed (or defaulted?) values of "Custom browser settings".

All of the above are in Win Xp and 7 environments.