Unable to open file...saveWebImage

[Ben]

I am trying PHP-Mapscript and have been having trouble revolving around
saveWebImage()

When I use it (I have downloaded the demo files from mobilegeopgraphics.com) I
am getting these messages :

Warning: [MapServer Error]: msSaveImageGD(): Unable to open file ~/Sites/
MSrecipes/tmp/1109776550141151.png for writing  in /Users/benmadin/Sites/
MSrecipes/hello.php on line 10

Fatal error: Failed writing image to ~/Sites/MSrecipes/tmp/1109776550141151.png
in /Users/benmadin/Sites/MSrecipes/hello.php on line 10

I have :
installed it on a Mac OSX.3 / apache server
set the permissions to rwxrwxrwx for theMSrecipes folder
created a tmp folder with similar permissions
changed the path in the .map file to incorporate a tmp/ directory with staff
permissions
tried using saveImage, which worked into the same directory that the files were in,
not the tmp/ directory - I would rather use the saveWebImage function I suspect
noted that the permissions for the .png files which saveImage wrote were www

I would be extremely grateful if anyone had any suggestions