Basecamp very slow startup on first opening of the day

I have a problem with Basecamp 4.6.2. Windows 7 x64. The first time I open Basecamp on any given day it takes several minutes to open. After that if I open it again it takes seconds. If I have had it open anytime during the day and I open it before midnight it takes seconds without rebooting but after midnight the first time I open it it takes minutes again. I think it's checking for something daily. Online maybe. Can I turn this behaviour off or do you know why it does this? and what I can do about it. I have reinstalled btw.