This came up in Raymond Camden's CFUnited presentation this morning and he suggested I blog it so here it is.

Problem:

You have extended the cfajax tags by calling the extJS functionality directly.  CF8 uses extJS 1.1 whereas CF9 is going to use extJS 3.0.  There will be cases it appears where this will break your code as some features have changed from the 1.1 to 3.0 release.

Solution:

1. Copy the needed JavaScript files (from /cfide/scripts/ajax/*) to another folder in the webroot (say /cfExtJS11/ajax/) and make sure you keep the folder structure.
2. On the top of any pages where you the cfajax tags use the cfajaximport tag:
   
   <cfajaximport scriptSrc="/cfExtJS11">

(Edit 10/14: I made a minor change to item 1 for clarification)