Warning: preg_match() & Warning: array_shift()

Hello,

I installed the last drupal version and the ckeditor and ckfilter module from scratch.
I encountered the following issue:

When I enter this html code:

<p><span style="font-size:24px"><strong>COOKIE</strong></span></p>

I get these warning messages:

Warning: preg_match(): Compilation failed: nothing to repeat at offset 229 in _ckeditor_filter_process_styles() (line 171 of /var/www/clients/client7/web32/web/ver34/drupal7/sites/all/modules/ckeditor_filter/ckeditor_filter.module).
Warning: array_shift() expects parameter 1 to be array, null given in _ckeditor_filter_process_styles() (line 173 of /var/www/clients/client7/web32/web/ver34/drupal7/sites/all/modules/ckeditor_filter/ckeditor_filter.module).

If I strip off style from the span element I don't get any warning.

<p><span><strong>COOKIE</strong></span></p>

It seems that what's causing these warnings has something to do with the span element and the style attribute or property.

Has anyone encountered this kind of issue?
Regards
AA