Compress Design is Deleting Tag Elements

We have recently started using AECOsim SS5 and are experiencing a problem with Compress Design.

In MicroStation v8i it has worked perfectly for many years, but in AECOsim it is sometimes deleting tag elements (Title Sheet tagsets) from the design file, can anyone see a reason for this to happen or has anyone else experienced this sort of behavour, or more importantly provide a solution. The problem cannot be always replecated so I am guessing it has something to do with the file settings left by a previous user or some other coincidence, as once I have reattached the tagset it all works ok.

Best Regards,

John Davidson.