Apply a extra generous amount of proofide to the bottom of the saddle and really work it in there. I've also been know to condition my Brooks saddles one time, by taping the vent holes closed on the top and flipping them over and pouring a capfull of SAE 10-40 motor oil on the bottom side and wiping it all aound. This is also a great way to "weather proof" it and protect it from rear wheel water spray.
Some people will swear by what I've done and some people will just swear I've ruined the leather.
YMMV