[Admins]

Well we figured out the problem - in old scripting engine the #k thing is ignored on serverside, and if you pass it to the client with say2 then the client is filling the key name in once it displays the sign text.
In new scripting engine the server needs to compile the script, but doesn't provide the keyname functionality itself. So it only works in clientside scripts or if you just pass the text to the clientside (by using the new scripting version of say2 with say2("blabla #k")).