Correction --> I see two implementations of isChildOf() in the other JAR files in framework.pack.js and prototype.js. However, I assume that neither of these js files is getting included properly when the tree tag and its descendents are rendered. Otherwise the function would be in the scope chain, right?
Any idea why this function remains undefined? (IE only. It seems to work with Firefox).
This files should be included with tree. Do you see any JS errors in IE7?
Yes. The error occurs in IE7. It does not occur in Firefox.
Please check all js files references from generated HTML. May be duplicates of prototype script for example generated by some other library?