Need Help - I am having a problem with trading ships in the diplomacy screen

I'm trying to give ships to allies but it seems that my fleet is too big. All the space in the diplomacy screen where the ships are listed are my starbases and constructers and scouts. The few warships that show up arent the ones I want to give away. This is making it impossible to assist my allies. Is there any trick or method for making the rights ships appear? Thanks