An Aladdin clarification last time stated that ShrinkWrap should be able to mount images that reside on HFS Plus volumes. However, several readers claim that this is not the case for them. For example, reader Gabriel states: "If I try to launch them from an HFS volume, they give me an invalid checksum error. If I copy them to a regular HFS volume, they work just fine." Benjamin Amsaleg claims the problem is related to the image file being fragmented. If you duplicate it and have an unfragmented copy as a result, it should mount.
Michael Baker describes a related ShrinkWrap problem: an inability to mount an image that resides on a volume larger than 4 GB. A system freeze may result. Aladdin acknowledged the problem. We commented on this basic issue last November.