I am using Joomla 1.5.25, K2 2.5.1 on a Linux server with Php 5.2.6
When I try to upload attachments I get the following error:

Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 24 bytes) in /public/sites/www.pvdabrabant.nl/administrator/components/com_k2/lib/class.upload.php on line 3036

I happens even when I try to upload a small .txt file with just 25 bytes.

I can't figure out what's wrong with it

I can upload pictures within K2 or with the joomla media manager.
On Main configuration I have max upload size set to unlimmited,
Max upload size is set to 16MB
Upload directories are set to chmod 0777

Someone who could point me in the right direction?

Hi Bart Pluijms,

Could it be the memory_limit in php.ini ?