Dumb "bad request" problem


OK I have a very simple problem, hopefully somebody knows the solution.

I have scgi Rails apps like this: app.domain.com

and unaccelerated Rails apps like this: www.domain.com/app/

the problem only happens with the second type of app, and could have a
lot to do with details with my host (a2hosting).

www.domain.com/app/ works – but www.domain.com/app triggers a “bad
request” http error.

totally just something for customer support @ my host? or something I
can solve myself with a line of code?

(the unaccelerated apps are of course destined for acceleration but I
want to put one into private beta immediately and I know some users
are going to skip the slash.)