i have a B&K in my living room set up as well and paid dearly for it around 4 years ago. that said, of course, i am reluctant to "let it go".
recently, i'm putting together a bedroom home theater set up. i got an Onkyo 807 receiver. despite its own miscellaneous issues with the Onkyo (the are sundry issues, not major ones), the fact that in the last 4 years or so, Audyssey has entered, allowing far better computer-analyzed room equalization, i feel that there's no comparison with what I had to go through for hours and hours on end when i set up the B&K 4 years ago with my trusty Radio Shack analog sound meter. that entire process 4 years ago now feels entirely quaint, and worse yet, entirely tiresome in contrast to the spiffy new Audyssey in the new Onkyo.
my suggestion is, at least to consider, getting rid of the B&K and getting the new Onkyo 2010 model 608 at an exceptionally good price (please see the Onkyo 608 thread vis-a-vis these good deals as price discussion per se are forbidden here). for a small amount, you will not encounter the issues you had mentioned in your post above.
of course, this suggestion might not sound appetizing to you at all as both of us paid a dear sum for our B&K's!! Yet, after my recent experience with my new Onkyo for my bedroom, alas, it's a brave new world now in home theater with Audyssey. It just ain't the same anymore.