phpBB3 attachments

[Gasdoc]

Hi
I'm setting up a phpBB3 forum and testing various functions on the way.
Today I attempted to use phpBB3's attahcment function. It worked once, but thereafter it failed. I found this error in the cPanel error log:

"ALERT - function within blacklist called: passthru() (attacker '91.109.163.110', file '/home/tciprop/public_html/forum/includes/functions_posting.php', line 621)"

Can you help me with this?
It is listed in the log the same number of times my attachment upload failed.
I was attempting to upload a picture(jpg) of a modest size with in phpBB3.

Is this a limitation of php on your server for security reasons or some other more complex fault.

Regards
Phil

 

[Gasdoc]

Sorry to bump, but is there a clever person there to have a think about my problem? Cheers.
Phil