Macrium has issued release 5.0.4995. This looks like an important release. I have attached a PDF with all the release notes. They are now stating that the various problems with the USB3 support have been solved.
What is also significant is that they recommend to burn a new WinPE recovery CD if you upgrade to that release. I have updated the .iso for the WinPE CD of that release at my Skydrive site