Now it becomes interesting. In order to avoid possible data loss I first need to fully understand the current situation.
As a first step, please provide a screen shot of the files you see in the VM's folder on the new datastore (names, sizes, time stamps). In addition to the screen shot, download the following files from the VM's datastore folder, compress/zip them and attach the .zip file to a reply post (you'll need to switch to the advanced editor to be able attach files). The files I'd like to see are the .vmx, .vmsd and all the .log files.
Btw. did you already try to remove the VM from the inventory and re-add it by right clicking the VM's .vmx file?
André