My cocoa app logs some "[Switching to process XXXX thread 0xXXXX]"

when I test my app in cocoa I can read some "[Switching to process XXXX thread 0xXXXX]" that I'm not understanding...

When app creates a thread?

For example, when I mouseover some main menu items, I get [Switching to process XXXX thread 0xXXXX]

Why?

Apple can reject my application of app store for this reason?

Thx!

It's neither an error, nor a problem. It's a normal part of an application running in the debugger.

Do the menu items have a custom image, or use any animation effects?

The messages in the debugger are only showing that the application has switched to another thread to handle the processing and unless I am missing something, I don't think there is any need to worry about them.

Our app, which has been in the app store for a few months uses images and animation on certain sections and gets process switching notifications in the debugger and has never been rejected for that fact.