[Typo3] Warning messages in my backend

[K-net]

Hi..

I'm still having trouble with warning messages in my backend ( running 
Typo3 QS 3.7.0 )
Now I get this message when I try to modify my template in the constant 
editor:

* * Warning*: ereg(): Invalid preceding regular expression in 
*/var/www/html/typo3/t3lib/class.t3lib_tsparser_ext.php* on line *1064

*I only get the warning(s) if I have changed the default settings in the 
constant editor  ( 1 change=1warning message - 2=2 - 3=3 etc. )

- Why does it appear ?
- Does this have any effect on my Typo3 installation because it seems to 
work anyway ?
- How can I get rid of it ?

Regards
K-net