Are you sure you want to change the extension from... BLOCKS Finder Editing

Question

This is weird and is driving me nuts, but some Macs do not allow further Finder editing of file or folder names if I change their names (usually including numbers, dots and so on) in such a way that I receive the warning:
Are you sure you want to change the extension from..?
After I confirm that I want to change the name, the Finder does it but gets locked for editing (I can do other things) and does not allow any further file or folder editing until I force quit of Finder or reboot the Mac.
I have found that if right after confirming that I want to change the name I select the file and hit return (which selects its name), no problem arises. But I must do it in one or two seconds, or else it will be too late.
IN SUMMARY:
1. Change file or folder name including numbers and dots at the end.
2. Get the message "Are you sure you want to change the extension from..."
3. Confirm that I want to change the name.
4. FROM NOW ON, I CANNOT CHANGE THE NAME OF ANY FILE OR FOLDER UNTIL I FORCE FINDER QUIT. Unless of course I do the trick indicated above real quick!
Any hint? Any way to know what is going on? This could be a bug of Mac OS X 10.4.x or earlier or a problem with a third party application. But how to know what is going on to prevent it? As said, some Macs show this issue, but not others.
Note: some related issues on this section searching for:
Finder Loses Keyboard Input
or
Sure change extension
For instance:
http://discussions.apple.com/thread.jspa?messageID=1974048
http://discussions.apple.com/thread.jspa?messageID=1466505
Hint: some file or folder name changes are more prone to cause the issue than others. For instance, renaming a folder (and confirming it) as:
Testing.r00
brings the bug 100% of the times.
Any idea of what is going on? Thanks.

Answer 1

The message is a warning that you are doing something that the OS thinks is going to possibly cause a problem. You are creating the situation and the OS is doing nothing other than what you are asking it to do.
I don't know any exact answer why you can't access your files, but I do know that there are a few characters and things that will cause problems because they mimic names of invisible files. When you make a name that is close to being the same it can treat the file as the special one... meaning you can only access it via Terminal.
Ones you cannot use at all: the colon (:), slash (/), single or double period as first characters. (taken from Finder Help with a naming files search) It is best to stay away from any special characters as a rule. Also avoid using a period and 3 character suffix unless it is one that you are purposefully assigning so the file belongs to an application.
That said... even with the over 200 applications on my system I couldn't repeat your Testing.r00 problem. So, I don't know if it may be application related or not.