It looks like there is a bug with the cftreeitem tag that was introduced in MX 6.1. Basically, the queryAsRoot attribute of the tag is broken. It no longer accepts a string value (it now only accepts a Boolean). This is inconsistent with other versions of CF as well as the MX 6.1 documentation.

The following code demonstrates the problem:

Note also that if you change queryAsRoot to Yes, the IMG attribute breaks. Instead of showing fixed, then folder, it shows fixed for both levels in the tree. Run the code on MX 6.1 and 6.0 to see the difference. I've reported this bug to Macromedia.