without knowing what if any error msgs you see in your status window:
-you may be rejecting the file type, file/options/dcc/folders
-you may have a script that refuses or puts ppl on ignore
-you may have dccs blocked, file/options/dcc or file/options/general/lock
-it may be a network that requires you /dccallow +nickname for certain file types
-the sender may be having the prob, not you