George - Moving data around within the TSM server storage pools has no effect upon retention policies. A policy change (retention or versions reduction could result in a lot of data expiring: your system change log should reflect such. Or it may simply be the result of an historic glut of data coming due for expiration, per your ongoing policies values. You can always run EXPIre Inventory with Quiet=No to see more of what's going on, and you can limit runtime with DUration.
Richard Sims
