Problem with custom action running on upgrade

[les bleus]

Hello,

I have a custom action that i want to run on an uninstall. I set it
with a "Installed" condition at the sequences execute. The problem I
am having is that the CA will also run when i do an upgrade.
How can i get around this? Is there a condition i can use for it not
to run on upgrade, since an upgrade also satisfies the "installed"
condition.

Thanks very much in advance for your help.