How to prevent UML Object Lifeline names from reverting to Object.

[Nick Piazza]

I have created a Visio file with (so far) four UML Sequence pages. While I'm
working on a page and adding Object Lifeline elements, I can type in a name
to replace the default names like Object1, Object2, etc. However, if I then
create a new page and later go back to a previous page, my assigned names
have disappeared and again been replaced with Object1, Object2, etc. I have
turned off UML semantic error checking in the hope of preventing this
anomaly, but it doesn't help. Can anyone tell me how to keep the names I
enter in the Object Lifeline headings?

Thanks
Nick Piazza