Version:           4.5 (using KDE 4.5.4) 
OS:                Linux

When doing a copy, KIO always runs through all folders before it reports any conflicts with existing folders in the destination.  If you have a lot of folders with a lot of files, you could drop a folder into a directory with the same name, then have to wait hours while it goes through every folder.  Only after it has run through ever sub-folder, but before it has transfered a single byte of files, are you given the option to give the folder a new name or write into the existing folder.  

This means you cannot just start the operation and then leave it, even if you know you want to give the folder a new name.  You have to pay attention so that when it finishes running through the folders you can tell it to rename the folder.

Reproducible: Always

Steps to Reproduce:
1) Create a directory (a) with a large number of sub-directory
2) Create a directory (b) with the same name in another directory (c)
3) Copy directory (a) to directory (c)

Actual Results:  
You have to wait until every single folder has been processed before you are warned of a name conflict between directory (a) and (b)

Expected Results:  
You are warned of a name conflict between directory (a) and directory (b) before anything else happens.