Banner ads appear while app is in background behind the home screen icons

[kendstar]

Hello,I am using AdWhirl both with House Ads and Ad Networks on my
iPhone apps.
One of my users is complaining that he sees one of my house ads even
after my app is in the background.
He says that he is opening my app and then closes it. Then he opens a
completely different app, for example the Apple Stock app, and then
when he closes that app he sees my banner for a split second on the
top of his iPhone screen behind the apps icons.
This behavior happens for the next ten times when he opens and closes
other apps.

I can't seem to reproduce this bug.
Is anyone familiar with this weird behavior?

Thanks

Roi

[wes]

Could he be using a jailbroken device?  I can't think of a single reason why he might be seeing this behavior.