[TYPO3-english] How to hide output of the t3lib_div::debug function?

[Michal Cygankiewicz]

I set [SYS][devIPmask] to my current IP adress. Unfortunately the output is visible for other IP also.
When I set this to blank value (which should deny all) - the output is also visible.

Should I set anything else (apart from [SYS][devIPmask]) to properly limit the output of t3lib_div::debug function.

I will be thankful for any help.