Gary, have you double-checked the "rights" to moodledata? I think the recommendation is 755 (which is where mine are), but you might even try 777. I think that you want to make sure that you apply these rights recursively (i.e., to all subfolders).
If moodledata is not within your public_html (or the Plesk equivalent folder), you shouldn't need to worry about .htaccess, I believe. But in checking my moodledata directory, I do see a .htaccess file in it. I cannot remember if I ever put it there, or if the Moodle install did this for me. I do see it in my experimental install of moodle, so I tend to think that it was created by Moodle. This one contains the following:
deny from all
AllowOverride None
Note: this file is broken intentionally, we do not want anybody to undo it in subdirectory!
You can email me at ads01@rjerz.com, if you need to.