I would be really really thankful to you for finding this tricky thing about moodle.

As i'm runnig moodle from localhost  in a linux environment , i faced the same problem (when i have changed my moodledata directory path) and could not find the solution.

Thanks a lot for your help.

And one more thing to mention:

Do not change the permission on /var directory to place your moodledata directory there (Coz one level up to the moodle (in /www) is /var) .

It will end up leaving you to install your linux OS again..

Coz in /var there are lots of usable security log files and you will not be able to access them..

thnx