The bug:

1. Add some random name irc server to a group list. Example:

Description: 123
IRC Server: 123.com
Group: Undernet

2. Now click "Edit" to modify it's description again. Example:

Description: Undernet: EU, CH, Geneva

3. We have now two entries with the same description in one server group list (the original geneva server and our modified server with the same description).

mIRC doesn't state the "A server with that description already exists" error.

mIRC should check for this error even when you MODIFY a server description.

Hope that helps...