There was a certain command in the past that delayed your messages. I think it was the "wait ---" command, where the dashes would be a value that would determine how long the message would be delayed for. Maybe this may have something to do with your problem? Perhaps you may have some text file that may execute this command when you're using scripts, that is, if you use scripts.
As I recall this command was also used to play as spectator in CTF, although they removed that little bug during the last update.
On a side note, is it really better to use the console to talk or is the Talk key easier? I've been using the talk key my entire life that's why.