HR21 kills my internet as soon as it is plugged into phone jack.

I haven't had it plugged into the phone jack except when first activating it.  Lately it has been popping up the "no connectivity" box on the screen.  So I decided to plug it into the phone jack to see if it would stop, and every time I have done it, it kills my DSL.  DSL comes back as soon as I unplug it.  I have a filter on the phone jack, and have tried multiple filters, so that isn't the issue.  Is it just hogging bandwidth?  Or am I missing something?