Normally you would set the share permissions to full control - everyone and then use the ntfs permissions under the security tab to make more granular and specific adjustments regarding your file or folder security. Anyway this is starting to sound more like a third party piece of software problem than an actual microsoft security problem. So take a look at any such software and make sure that you don't have something else actually preventing anytype of network access. Then adjust your security settings for your test project as I suggested above, and always use the ntfs permissions to get specific regarding read, write, modify, etc. Test if need be, full and full, (for your test user) and then back it off a little a see if you can...