I think the problem is with the include path.... it looks like it's trying to include from /usr/local/lib/php.... it should be trying to include from your site...
Try going to your admin panel, Domains->Manage, select the Web aspect to your domain and click Edit next to it, then untick the "Run PHP as CGI?" and "Extra Web Security?". See what happens. You will probably have to wait for a while. If you are in Europe area, then it's night time so just save the changes and see what happens in the morning.
If you are getting information from the database, including test.txt won't affect that. It seems your problem is trying to include files. Did you take my suggestion and just put that test file at the same level as your text file (ie same folder
(and renaming the
I've not had any problems including files, my own web site includes about 5 files every time it's loaded.....