It is usually the long URLs that increase the margins. There is a way to post long URLs without showing them:

      *url=Long_Long_Long_URL_here]Go_see_this*/url]

   Except the '*' character represents the '['. That way only your description, "Go_see_this", shows in your message and not the actual URL they are going to.

   I wish the Pet Talk software was easier to use. Here is what it looks like with ['s instead of *'s.

      Go_see_this