MSG HD doesn't work, but MSG+ HD does!? Comcast to blame?

As I write this, I am watching the first period of the highly-anticipated Rangers-Leafs re-match on Toronto ice after New York's 7-2 trouncing at the Garden in pitiful 720x480...

ON MY BRAND NEW 56" 1920x1080i SAMSUNG LED TV!! I got this thing for crystal-clear sports games in HD, particularly the Rangers and Knicks, yet I am currently handicapped into viewing my heroes in crumby 720x480!

I have watched all of the other MSG broadcasts on channel 196 (MSG HD) in glorious high-def. I even had the Comcast personnel visit my home twice in the weeks preceding the pre-season to fine-tune the connections and remove excess signal degradation.

For game archiving purposes, I can deal with the weaker signal as my DVDs are currently done in 4:3 anyhow, but I like to actually watch the games in their pinnacle of available clarity and this is deeply-upsetting!

So here's the problem (and what I told the Comcast call-center receptionist):
When there are HD feeds from both MSG and MSG+, only one of them will work. Tonight the Rangers are on MSGHD (196) and the Devils are on MSG+HD (197). My television [as well as another HD TV in another room on another box] detects 1920x1080i feeds from both channels, however 196 is completely blank.

The same thing happened last night while the Knicks (196) were on at the same time as the Islanders (197). I had to watch the Knicks pull off a come-from-behind victory featuring a glint of optimism on my shiny new TV on 720x480 then, too.

Two nights in a row, MSGHD has been silent blackness while MSG+HD has shown the games I couldn't care less [aside during commercials and intermission] about in brilliant capacity.

Anyway, a Comcast cable technician will be, once again, visiting me on Monday. Because this problem can only be replicated when there are HD feeds on MSG and MSG+ simultaneously, I do not foresee a technicians visit as a productive course towards a solution. Perhaps a change in provider is on the horizon..