Hello,
I've recently bumped into a dojo.addOnLoad bug with IE6: It can execute the passed function even if document's readystate is currently "loading".
Here's a way to patch dojo.addOnLoad:
//dojo.addOnLoad patch if IE
if(dojo.isIE){
//Saving a copy of the original function.
var origAddOnLoad=dojo.addOnLoad;
//Wrapping it.
dojo.addOnLoad=function(){
var args=arguments;
if(document.readyState=="complete"){
//Document is loaded. Removing the wrapper.
dojo.addOnLoad=origAddOnLoad;
dojo.addOnLoad.apply(dojo,args);
}else{
//Document not loaded yet. Deferring execution.
setTimeout(function(){dojo.addOnLoad.apply(dojo,args);},10);
}
};
}
This code should be put in your own dojo module. So dojo might be in memory right before this patch is executed.
Pascal.

If you can file a test case
If you can file a test case at http://trac.dojotoolkit.org, that would be appreciated. We would like to fix the issue in the toolkit if we have a test case to confirm the fix. You can use the login/password of guest/guest to create a ticket and upload the test case.