When I try to upload something on the forum from a url I get the following message:

Warning: fopen(): SAFE MODE Restriction in effect. The script whose uid/gid is 13250/13250 is not allowed to access / owned by uid/gid 0/0 in /includes/class_upload.php on line 269

Warning: fopen(/temp/vbupload19932): failed to open stream: No such file or directory in /includes/class_upload.php on line 269

this problem also happens when I try to upload an avatar from a url

I think that it has something to do with a temporary folder.

Could somebody help ?

добавлено через 39 минут
found the problem and fixed it but now I have another one:

Does anybody know how to make the boarder around the attached thumbnails smaller or get rid of the boarder ?

Because of the big boarder my whole post stretches out of the forum boarders as you can see on the image below.

Admin control panel
vBulletin options
Server Settings and Optimization Options

You need to setup properly this options:

Safe Mode Upload Enabled [Yes]
Safe Mode Temporary Directory [correct tmp dir ask hoster, i think its not in phpinfo but also check it]

also probably you can try to change chmod for class upload php file (from your message text)

yeah the attachments work now but I'm having problems with the border now, I edited the post with the information

There's no way to fix it for a fixed-width style, changing the border will not help you. You could however decrease the thumbails' size.

I see well that's a shame, thank you will decrease the thumbnail size.