Run the script that you find on the bottom of this page: http://manual.b2evolution.net/Debugging#Permissions

- Copy the code
- paste in a new file
- save that file as 'permission.php' or similar
- transfer to your media folder yoursite.tld/blog/media/
- run the script from your browser: yoursite.tld/blog/media/permission.php

It will tell you what's wrong and why.

Good luck

I couldn't even run it at first...got a forbidden message. I changed the permissions on the root and on media to 777 (again) and it let me run it finally. But this seems not right, perms.php is the script file

Current script owner (irrelevant): purpleme
Process user:nobody
Dirs:

Effective perms are highlighted/bold.
Green user and groupnames can write.
Brown user and groupnames can read.
Red user and groupnames cannot read/write.


      Warning: fileowner() [function.fileowner]: stat failed for /home/purpleme/public_html/banpuppymills/b2blog/media/media/ in /home/purpleme/public_html/banpuppymills/b2blog/media/perms.php on line 33

      Warning: filegroup() [function.filegroup]: stat failed for /home/purpleme/public_html/banpuppymills/b2blog/media/media/ in /home/purpleme/public_html/banpuppymills/b2blog/media/perms.php on line 34

      Warning: fileperms() [function.fileperms]: stat failed for /home/purpleme/public_html/banpuppymills/b2blog/media/media/ in /home/purpleme/public_html/banpuppymills/b2blog/media/perms.php on line 49
    * /home/purpleme/public_html/banpuppymills/b2blog/media/media/:
      / root/root
      Warning: dir(/home/purpleme/public_html/banpuppymills/b2blog/media/media/) [function.dir]: failed to open dir: No such file or directory in /home/purpleme/public_html/banpuppymills/b2blog/media/perms.php on line 95

Does this script run in a media folder that is not affected by the weird behaviour. I'm starting to think something is fundamentally wrong with that folder. If it's empty you might try to delete it and create it anew.

Good luck

There's nothing in the folder so I'll delete and recreate.

I moved it to the conf folder and tried, same thing:

Current script owner (irrelevant): purpleme
Process user:nobody

Dirs:
Effective perms are highlighted/bold. 
Green user and groupnames can write.
Brown user and groupnames can read.
Red user and groupnames cannot read/write.



Warning: fileowner() [function.fileowner]: stat failed for /home/purpleme/public_html/banpuppymills/b2blog/conf/media/ in /home/purpleme/public_html/banpuppymills/b2blog/conf/perms.php on line 33

Warning: filegroup() [function.filegroup]: stat failed for /home/purpleme/public_html/banpuppymills/b2blog/conf/media/ in /home/purpleme/public_html/banpuppymills/b2blog/conf/perms.php on line 34

Warning: fileperms() [function.fileperms]: stat failed for /home/purpleme/public_html/banpuppymills/b2blog/conf/media/ in /home/purpleme/public_html/banpuppymills/b2blog/conf/perms.php on line 49

/home/purpleme/public_html/banpuppymills/b2blog/conf/media/:
/ root/root
Warning: dir(/home/purpleme/public_html/banpuppymills/b2blog/conf/media/) [function.dir]: failed to open dir: No such file or directory in /home/purpleme/public_html/banpuppymills/b2blog/conf/perms.php on line 95

Deleting and rebuilding seems to have done the trick.

Thanks!!