Problem is most people have no idea what the problem is...
Apple pays its taxes in the countries it makes its sales. The problem is the US wants to charge the difference between the country rates and the US rates when Apple tries to move the cash into the US. The result is the cash stays offshore unless the country has a >= 35% tax rates, in which case Apple can bring the cash to the US without additionnal charge.
For example, if Canada tax rate is at 25%, Apple pays 25% to Canada on sales made in Canada. But if they move the profits made in Canada to the US, the US wants another 10% on top of what Apple already paid (35% - 25% = 10%). This is where the US system is flawed.
This has absolutly nothing to do with tax dodging. Apple does do it with itunes sales in some cases (example: itunes ireland hub deserved the EU), but not with hardware. Tax dodging with software sales or ads is a major problem with Google and Amazon, but not Apple.