My question involves unemployment benefits for the state of: Wisconsin

I am asking this question on behalf of my girlfriend.
Her story goes:

She is an hourly production employee in a manufacturing company. Her "normal" shift would be from 2pm - 10pm. There are occasions when her boss will change her hours with less than a 24 hour notice. Example, its a Thursday, she comes in on her normal shift, at 2pm, and boss tells her that she need to work Friday 10am to 6pm. This in itself is not necessarily the issue. The problem is that they want to temporarily change her to 10pm - 6am because that is the only shift when work is available. She doesn't want to work that shift and her boss says that if she refuses to work those hours they will deny her unemployment benefits.

Her boss talked to her about this last Thursday and last Friday she was laid off due to lack of work. So her last contact with her boss was the previous Thursday, which she expressed her unwillingness to work that shift, and he didn't give a definite answer about her work schedule this week. So he calls this morning, Monday (6/7/10) and leaves her a message saying, "I want to make sure we're on the same page with you coming in and working 10pm - 6am, ect..."

Now, because she works Thursday nights at a bar, he said she can come in on her normal shift on Thursdays, 2pm - 10pm, but that's after she had worked the previous Wednesday night 10pm - 6am, and then they will probably change her Friday hours to who knows what.

So can a company arbitrarily change a employee's hours like this, without a schedule, and if the employee refuses to work those requested hours, can the employee be denied UI benefits?

I tried to give as much valid information as I possible could. I'm guessing she doesn't have much of an argument but I figured I'd ask anyway.

Thanks