system:open-url and Google Chrome on Windows, LispWorks 5

I don't have LispWorks 6, so I can't report for that, but in LispWorks 5
when my app calls system:open-url on Windows, if the users default
browser is Google Chrome then a restart is thrown. I don't have the
exact wording, but it is something about an unexpected application and
one of the  restart options is 'continue as if Internet Explorer'.

This behavior seems to only occur with Google Chrome, not Firefox.

I'm about to go hunt up the exact case so I can programmatically invoke
that restart.