Forcing a rebuild of an Enterprise Portal project?

I'm having a bit of difficulty with the Netweaver Developer Studio version 7.0.11.

I can only test changes I've made in code by re-deploying a .par file to our sandbox portal once. I then have to delete a generated .par file and export instead of do a "Quick PAR Upload" or else I get a message that the connection was refused. If I don't delete the generated .par file then the changes won't take effect at all - it simply refreshes the project on the server without taking in to account any of the changes I've made.

In the Workbench preferences I have all of the options checked. When I select my project, go to the project menu and select "Rebuild Project" or "Rebuild All" the only thing that happens is a quick flash of a progress bar that would normally indicate a rebuild is in progress, but it just doesn't take place. I used the project that already exists from my last build.

Is there a better work-around than what I'm using (deleting and exporting) or a way to force manual builds to work right the first time around?

I'd appreciate some help on the matter. Thanks.