Not sure if Azure cache has recently changed, however the access keys seem to have a slightly different format.
I followed the instructions from here: http://msdn.microsoft.com/en-us/library/windowsazure/gg618003.aspx
I setup the cache factory programatically and it works a treat. However, after I added another cache to our system, the new cache doesn't work. The error I get is:
ErrorCode<ERRCA0029>:SubStatus<ES0001>:Authorization token passed by user Invalid.
I'm accessing the cache in the same way as before, only difference is the different host and the different key.
The first cache I setup (that is working), has auth token that is 232 characters long. the new cache has a key that is only 204. Not sure if this is relevant but I'll give as much info as possible.
The instructions on http://msdn.microsoft.com/en-us/library/windowsazure/gg618003.aspx are for working with the same cache but with distincts endpoints. For example adding https access to your current cache.
If you wish to work with 2 Azure Cache, just build 2 distinct objects with 2 independent implementations.