Web Services [Magento]

Can anyone make this work?

I'm trying to connect to/consume a webservice from a Magento commerce store [written in php] but am having problems with coldfusion not being able to "find" the methods I need to invoke.

- I can create the object, log in, get a session but nothing [NOTHING!] else, none of the other methods are available - I just get a method not found error.

- the user "register" with key "register" has permission to use them and I can [have] prove that it works, I can for example call up  the store category tree VIAcatalogCategoryTree.

- the dump of the mage_obj shows all the methods available.

- The webservice is a Magento store [http://www.magentocommerce.com/]

- The API documentation is here http://www.magentocommerce.com/support/magento_core_api

- the webservice url is live, up and a test instance, so I am not afraid of it getting broken, please test to your heart's desire!

<cfscript>

mage_obj = CreateObject(webservice, http://mage.bigblock.ca/api/v2_soap?wsdl);
 mage_session = mage_obj.login('register','register');

//retcat = mage_obj.catalogCategoryTree(mage_cats);

</cfscript>

<cfdump var="#mage_session#" />
 <cfdump var="#mage_obj#" />
 <!---cfdump var="#retcat#" /--->

If anyone can take a look, give this a try - give me any clues as to why I can't access the webservice VIA CFMX, I would REALLY-REALLY appreciate it.

I've been struggling with it for better than 2 days now. [more than 4 days now]

- thanks in advance

-sean