Perforce plugin doesn't always checkout files? Follow

I have the Perforce plugin installed in Idea 4.5.3

When I try to edit a file, I am prompted that the file is read-only, would I like to edit the file. When I click Yes, sometimes the file is checked-out of Perforce and I the read-only flag turned off, but most of the time nothing happens and I have to check the file out manually.

Has anyone seen this behavior and is there a setting or update that fixes it?

thx
andy