[ic] Won't calculate shipping

[Michael Michaelsen]

My last two problems have been caused by bugs in ver 4.7.5 so I wonder if this could be another one.
I can't get the cart to calculate any shipping cost. No matter what I do it come up with $0.00 shipping cost. I have set the shipping preferences in the setup wizard to a $4.50 flat fee.
In administration/shipping I have configured FLATD also to $4.50 and I have tried to set a minimum to $4.50, but nothing is applied when I check out.
Any help on this one?