I am having the exact problem as well.. Mine wont start in 90 degree weather.
riceetr, does your clicking change pace when you hold the clutch in? mine does and it seems odd.
My battery is always charged and i now have two of them sitting around, thinking one was having problems before. It's gotta be in the starter somewhere, mine is consitantly getting worse. It wont start at all now.
Welder, it would be awesome to hear what you learned about the issue. Do i need to buy a new assembly? (2007 XB12Ss)