I have the same problem, I'm trying to develop a site that uses jCarousel, and keep all of my other jQuery functions in another file. As for now I have to choose between the jCarousel functionality and ALL other jQuery-functions, I can't get them both to work!
In Firefox Firebug I get the "$ is not a function" error on my js-file. I've changed all the "$" into "jQuery". It doesn't give error messages, but none of the functions in my jquery-file works. I've even tried adding a simple jQuery("h1").click() function with an alert, but no reaction, and no error messages.
I'm guessing it has something to do with .noConflict()? The jCarousel js-file has "jQuery.noConflict()" on the first line. I've tried removing it, changing it to "$.noConflict()" in both the jCarousel-file as well as my own js-file. No luck. Any ideas?