Not returning phone calls to some businesses

Surely it's just an oversight. Her campaign isn't broke, is it?

She has $33M in the bank, but only $11M is spendable on the primary; the balance is reserved for the general election, and must be returned if she's not the nominee.
The campaign's been spending big on media and delaying paying its other bills.
So yup, she's getting short.

It is common knowledge that most campaigns tend to be foot-draggers on paying bills. I would bet there are similar frustrations from Obama's and McCain's vendors.