getJSON Pound Sign problem

getJSON Pound Sign problem

I've got a search application that uses the autocomplete plugin and ajax to query Solr via Spring MVC.  If a user enters a pound sign it gets passed through to Spring via ajax ok, that is after I set Tomcat URIEncoding="UTF-8".  Prior to this a pound sign came through to Spring with a capital A character with a carat above it in front.

In another part of the application I am using getJSON to obtain some data, using the user input as part of the url.  Unfortunately, when these requests are retrieved by Spring the pound sign has this strange character again in front of the pound sign.

When using the ajax call I use
data: {
             q: request.term
          },
to pass the user input through to Spring. 

With getJSON I use the value from the input field and build it up into the url string.

I understand the problem is something to do with UTF-8 conversion but I was wondering whether I anyone could shed any light on why the ajax call works correctly but the getJSON doesn't, and whether there was anything I could do to get the getJSON call to work correctly.

Thanks
Shaun