Comment 6 for bug 297077

First of all, I don't think it can be stressed too often that turning on backports without using pinning is generally a very bad idea. For maximum stability you want to only pull in specific packages from backports.

That said I think a solution to this problem would be that (roughly):

* xen-utils 3.3.0 should depend on libxen3 >= 3.3.0 and should conflict with libxen < 3.3.0
* xen-utils 3.2.0 should depend on libxen3 >= 3.2.0 and should conflict with libxen >= 3.3.0

I'd say these are SRU worthy fixes and once backported would prevent this issue as well as a few others.