[TYPO3-english] Frontend editing error

[Sergio Catalá Gil]

> Please start updating your TYPO3 version to latest stable to get rid
of 
> security issues. Then see if by chance it solves your bug and if not, 
> post an update statement here. Thanks.

Xavier, 

I updated TYPO3 to 4.2.8 version but the same error still remains. It
only shows when trying to create some kind of content through the FE
bar:

Fatal error: Call to undefined method tslib_fe::hscAndCharConv()
in /var/www/my_site/typo3_src-4.2.8/t3lib/class.t3lib_tceforms.php on
line 4784

Any ideas?

Thanks in advance, 
Sergio