I had the the following error during Create Collection: Warning: mkdir() [function.mkdir]: Permission denied in plogger\plog-admin\plog-admin-functions.php on line 1230
I changed permission to read and write for all folders and files in plogger folder also root folder using FileZilla, but it doesn't have effect.
After that I switched to use my host control panel, then I changed permission to read and write for all folders and files. The problem was solved.
I prefer to use your host control panel to check root folder permission.