This came from a PUMA in Denver. Apparently the DNC is so SCARED of Hillary that they would rather have NO roll call than the chance that she could win it. Looks like Donna Brazile is playing real hardball here:

the Big Shots are STILL planning a work-around. Now they’re talking about a closed door written vote on Wednesday morning with no established Chain of Possession. No roll call vote is the threat.
THIS is why the Hillary supporters are angry. Not because they hate Obama but because the dirty tricks the DNC is playing on its own people are of the highest order.

(In my case, I really do hate Obama. :) But I don't like anyone with zero credentials getting the big prize.)