I also have VMDK file corruption using workstation 9 and Windows 8 Storage Spaces.
I'm using a mirrored storage space (two-way mirror) with identical disks. No other software apart from VMware has any corruption problems and I have individually tested each disk to be OK.
This has been ongoing since the release of WS9 and I've updated it to latest version but no fix. Moving the vm's onto non-storage pool stops new corruption from appearing. However I do continue to run test machines from the storage pool as that's where most of my space is.
I agree that this must be some bug in vmware workstation 9.
I did contact VMware and lodge a support request. They were very helpful but unable to resolve other than recommend to not keep my vm's on the storage space. They couldn't reproduce from their end so at least its reassuring to see other users with the same issue.