To debug this problem please try follow the steps below and feedback with the information:
1) Open a terminal window by navigating to Application > Utilities > Terminal
2) Type in: cd '>Library >Application Support > Adobe > CS5.5ServiceManager > extensions > AppStudioExporter > cli'
3) Type in: ls -altr
4) one of the lines of output should be something like the below...
-rwxrwxrwx 1 <yourusername> admin 854 18 Nov 10:53 pressrun.sh
... if that line for 'pressrun.sh' doesn't start with -rwx then get a system admin (at the company, not us) to change the permissions of all the files to give execute permissions, or if the user is allowed to install and such on their own computers then just run: chmod 777 *
If the permissions were already ok then ...
5) Type in: ./pressrun.sh -u <your email here> -p <your password here> -h my.appstudio.net pubs
eg: ./pressrun.sh -u firstname.lastname@example.org -p mypassword20 -h my.appstudio.net pubs
6). Please send us the response or take screenshots and attach to the ticket.