JMeter + HTML Unit + Webdriver Issues

Hi All,

I've been trying to test a few sites with complex JS with htmlunit /
webdriver and I'm getting some error. For example, the new ghost blogging
platform login page:
http://192.241.254.227/ghost/signin/

Simply doing a plain page get gives errors:
WDS.browser.get('http://192.241.254.227/ghost/signin/')

Any ideas why?
It works fine with the chrome webdriver config.

I did some research and found that changing the default user agent in
HTMLUNIT often helps, but I can't figure out how to do so.

Thanks
Ophir