@Cableman, I understand your situation… the thing is that there are thousands of hosting companies with different configurations and stuff so even though I know that the plugin will work on 95% of the servers off the bat but there is always going to be that 5 or 10 percentage where it will need a little push. Lets try to identify the issue first so I can see what needs to be done.
Questions for you…
1) Have you changed any code in the plugin?
2) Do you get emails from your wordpress site when someone leaves a comment on your site? This indicates that wordpress is mailing stuff out fine.
3) Have you run the test transaction in Debug mode? This is suggested in the “How to Test” post (http://www.tipsandtricks-hq.com/ecommerce/how-to-test-the-wordpress-estore-to-make-sure-everything-is-working-properly-35)
4) If the answer to question 3 is yes then can you please share the contents of the “ipn_handle_debug.log” file?