The problem is with this:
# ls -la / | grep qwer
drwxr--r-x 2 coolmax coolmax 4096 2013-02-27 19:06 qwer
Directory 'qwer' has no write or execute permission for group members. See this part (marked in Red):
And since 'coolmax' is a supplimentry group for user 'www-data', so he cannot write or execute the directory i.e. cannot see it's content.
So simply solution to this problem is to add at least execute permission for group on qwer directory, as:
~$ chmod -R g+wx qwer
Either user 'www-data' should be member of 'coolmax' group and 'qwer' dir. should have write/execute permission of group OR, 'qwer' directory shold have all permissions for others.