Dual carb "chirping" at 1/2 throttle?

I've got a set of dual 40 mm Dellorto carbs that chirp when the throttle is opened up half way under load. REAL annoying. I had a set of dual 45 Dells with choked down venturis running identical jetting as I am now on the same engine without the annoying chirp, so I know it's the new carbs. I origionally thought it was the belt because it sounded like a belt type noise only a little too loud for that. After checking tension and a can of belt dressing, I have rulled it out. Has anyone encountered this and, better yet, solved it before?

[wjdunn3]

I have the exact same problem. It started when I installed 32mm venturies AND did some "porting" work between the cleaner base plate and carb top. I thought the chirp was caused by the "porting" I had done? I have not had time to tear back into it and figure it out.
I would be really interested in your jet configs. I am running stock heads, a cam ground to favor the high RPM range (eagle cam from CB Perf). I have tried many jet configs. none give me the throttle response I am after. Currently I have .55 idle, 1.5 main, 32mm vent, 1.8 a/c, .40 a/pump, #2 air corr, 1.5 inlet. When I had the carbs setup as "factory" I had terrible on-throttle hesitation at any RPM.