Table margins not saved

A user creates a table in a rich text field, saves and exits the document, re-opens the document and the table is shifted about one inch to the right. With each successive save/exit/re-open sequence, the table shifts farther and farther to the right.

Changing the margin settings is only effective while the document is open - the settings are lost when the document is saved.

Anybody else see this behavior? Anyone have a fix/work-around? TIA.