Mac OsX Mail program problem


i am currently running osX version 10.2.8 with the built in Mail software version being 1.2.5 v553.
the problem i am having is there is alot of mail stored in there, so i created a seperate subfolder to organize stuff, the folder is about 1.1 gigs in size and stores some 1200 odd messages. i can look in the folder thru the client, i can see the headers of the messages (who its from, what its titled) but when i select any mail to read it, it tried to retrieve the message and just hangs there. and its only that folder, all the others are fine. any ideas as to whats going on?

Have you tried waiting for a few minutes? With a folder that big, it may take Mail a minute or two to actually retrieve the message...