imagemagick not responding

After installing of imageMagick on a Debian M开发者_如何学编程achine (debian_version 6.0.2)

Running this command:

/usr/bin/convert -scale "90x>" -quality 80 -strip "/right/path/source.jpg" "/right/path/destination.jpg"

doesn't save the destination image in /right/path/ and returns no errors.

"convert" is found into /usr/bin/ so that's where the command should be launched from...but nothing happens...

permissions are set "775" for each folders i'm saving the file in.

writing:

echo exec("whoami"); 

works and returns "www-data" wich has any kind of permissions

Any clue why/what to do?

Thanks.