Rights Enabled PDF and Internet Explorer

Hello,

Our company is considering purchasing an online proofing system. The way it is supposed to work:

We make a pdf and enable commenting rights in Acrobat 8 Pro.
We upload this to a database on our proofing server.
The client goes to our proofing domain (URL) using Explorer or some browser and clicks on a pdf from our online database. This opens the pdf in the browser's Adobe (Reader 8) plugin.

The user SHOULD be able to comment using the commenting tools. However,

When you click on the info for the pdf, its says the user has the right to make comments. But the commenting toolbar is unavailable. So you cannot comment.

Is there some preference setting in Adobe 8 Pro when you are enabling rights, or in Internet Explorer, or even in Adobe Reader 8 that needs to be set in order for the commenting toolbar to show?

Thank you.