drop down field size

I can't get the drop down field sizes to be large - when I choose large as the field size the width is still really small so the options don't fit in the box.

Any ideas why this should happen?

Surething http://mepa.stipa.org.uk/candidates-pages/questionnaire-v1-1/

When I'm actually editing the form the boxes are the correct (large) width.
When I click on the preview button however the boxes revert to the (too) small size.

Have sent the form and another where the uk centre drop downs are the correct size but the Canadian, USA and Other drop downs are too small.
Thanks!

Interesting, yeah it is only if used on the conditional logic. I'll bring it up. For now, Matt, you can use the below to get you rolling. I targeted the specific drop down on your Questionnaire v1.1 form instead of a doing a global target. If you'd like to use this method on other conditional logic hidden enhanced drop-downs, just make sure to ID the correct input either by viewing the source, using Chrome Dev Tools or Firebug for Firefox.

[css]
#input_3_6_chzn {
width: 98% !important;
}
#input_3_6_chzn .chzn-drop {
width: 99.6% !important;
}
#input_3_6_chzn .chzn-search input[type="text"] {
width: 94% !important;
}

Thanks Rob, will give it a whirl!

Yep 1.6.3b2 works for me too!
In fact all the layout looks clearer.
Good job!