Dan, are you running WebUI Studio 2009?

There are two ways you can reduce the footprint for slower connections:

1. If you're using WebUI Studio 2009 already, you can take advantage of the new compression filter which is designed for SmartWebResources feature. Make sure SmartWebResources is enabled (which loads scripts from ISRes.axd instead of physical file), then simply add one line to your web.config:
   
   

   <add key="ISNet.WebUI.ISRes_Compressed" value="true" />
   

   With the simple line above, the scripts will be automatically compressed using gzip or deflate encoding depending on the browser capability (most browsers today accept both gzip and deflate encoding).
   
   With compression enabled, the overall footprint size for scripts can be reduced by 80%. This will dramatically improve the application speed especially in slower connections. 
   
   

2. If you're not using WebUI Studio 2009 yet, or if you don't use SmartWebResources, but you used IIS 7 (Windows 2008) to host your applications, you can use IIS 7's built-in compression. Similar to our compression model, IIS 7 will then automatically compress your scripts depending on the browser capabilities.
   
   To learn more on how to configure IIS 7 compression, please refer to Configuring HTTP Compression in IIS 7.
   
   

Hope this helps. Let me know if the solutions above worked for you.