I've created a number of modules that are very basic which have worked prefectly. I've now hit a brick wall as I've created a new module which is very basic and Im unable to add it to a page.

How can I work out what is preventing me from adding the module to a page to allow me to debug this?

Any ideas on why this is happening or a way for me to debug this would be gratefully received.

 Ok, I've cracked it! I'm posting this to ensure that no one else feels the pain I went through!

Basically I used the excellent examples from http://www.adefwebserver.com/DotNetNukeHELP on Linq and everything was fine when I followed the example word for word. But then I started doing it from memory and thats when things went wrong. 

What you need to do is make sure  when you are putting the control details in for the module definition, you do not put a key in. I did this and the module was not displaying. Hopefully someone will be able to explain why. But for the time being, if you are doing module development and you experience the same problem, take a look at your module installation!