Odd Domain Forwarding Issue

I am having an odd issue - and wondering if anyone has had this happen to them and found a solution.

I have a domain at whatever.com
I have a folder whatever.com/example
I have an additional domain forwarding to whatever.com/example and the domain is called example.com

I have set up the paths correctly I believe.
FCK editor only works if I goto whatever.com/example and not if I goto example.com

Well I am using full paths so domain names shouldn't be an issue. But I messed around with it and changed it to be tailored to example.com

Alas it broke for both of them. Then for no reason I checked it in IE - and IE gave me an error saying permission denied for the paths for fckeditor.php

Well...I reverted back to my previous code and it worked for whatever.com/example and not for example.com just like I expected - and tested it in IE again. Worked fine for whatever.com/example and gave me the same error for example.com

Why is it giving me this error? Permission denied?
Is this a server side issue and something I should let me host fix or is this something I am being retarded about.

All comments/questions/answers are welcome and will be helpful.