Your nickname contains the following invalid characters "()".

[nolazabal]

i have always used (name) on my nickname and now when i try to conenct any server it give me this message:

Bad Login (name and/or password wrong)
Your nickname contains the following invalid characters "()".

why just starting today i get this message?

[guldi]

cause those chars are prohibited in the current TS server version (already posted a MANY times here !). Server admin can set them in the server.ini

if you want to know more, do a search or read the news coming with the server (I belive it's noted there)