How to get rid of annoying "Are you sure you want to remove the selected.."

I'm using iTunes 8.0.2.20 on Windows XP Pro + SP3.
The first time I removed some songs from my library I got the following prompt:
"Are you sure you want to remove the selected songs from your iTunes library?".
A checkbox also allowed me to prevent this prompt appearing again. I checked the checkbox and clicked Remove.
The next couple of times I removed songs from my library I received no prompt - perfect.
Suddenly, the prompt appeared again, but this time there was no checkbox providing me with the facility to stop the prompt appearing.
Then, next time, the original prompt with the checkbox appeared (already checked).
What's going on? This looks like a bug in iTunes 8.

Can anyone tell me how I can get rid of this extremely annoying prompt once and for all? This is the type of poor coding I would expect from Microsoft, but not Apple!

Thanks.