URL aliasing

Hi, my website uses a CMS which features URL aliasing. They claim that search engines pick up just the URL with the keyword alias you configure in their system, but I'm not sure that is what's happening. Quick example:

We have a page here:
mydomain.com/generic-folder/keyword.aspx

and we set up aliasing so that you can just go to:
mydomain.com/keyword

to get to the page. (you still only see the /keyword in the url).

The issue is how Google is indexing this. When I search for my keyword phrases, the url of "mydomain.com/keyword" is nowhere in Google's index. Instead, they have picked up "mydomain.com/generic-folder/keyword.aspx".

My question is - which URL is best for Google to have in its index? I would think mydomain.com/keyword, no?

mydomain.com/keyword is probably easier for users to remember, so I'd say go for that one.

Thanks, this is why the URL aliasing is used, so that people can remember just mydomain.com/keyword

The problem, however, is that Google seems to be indexing the URL that we're trying to alias, instead of the plain and simple "mydomain.com/keyword". Make sense?

So if you search for my keyword, Google returns the URL of mydomain.com/folder/keyword.aspx. It doesn't seem to have indexed mydomain.com/keyword at all.

I'm considering removing the alias and placing my content at mydomain.com/keyword instead. I just wonder if this makes a difference in the eyes of Google-bot?