Hi Stacy,
When the editbox does not have the focus, what are the property settings for:

enabled
disabled
readonly

Are you setting any of these properties for the editbox in the command button in whose click method sets focus to the editbox? I had something similar happen to me like this when I changed the readonly property programmatically from another control. I don't know what exactly causes it or what will fix it, but I started using the disabled property instead to enable/disable it and that worked for me.