Hi,
This doesn't happen on our Live Demo:
CleanMart
Attachment ScreenShot2015-03-29at2.58.52PM.png not found
SportMart
Attachment ScreenShot2015-03-29at2.58.59PM.png not found
So, it must be happening because one of your Joomla Template's CSS file is trying to re-style that shipping lists items (and define a width css rule). That rule needs to be eliminated.
Unfortunately we don't provide free support or step-by-step instructions if the problem is not happening directly because of our templates.
You may purchase premium support:
www.flexiblewebdesign.com/premium-support
and let us take care this modification for you directly on your website though.
FYI: See this topic if you are willing to fix this CSS problem by yourself:
www.flexiblewebdesign.com/forum-virtuemart-2-template-puremart-support/342-using-firebug-for-customization-or-troubleshooting
regards.
Regards.
Support