Would it be for the same reason that it takes too long to shutdown? My laptop (dualboot - ubuntu/windows) takes significantly longer to shutdown when on linux. Even with the SSD - which made windows really faster.
I have another laptop that takes about a minute to shut down, and it appears related to the wireless NIC. While it's an Intel-based card (Killer-rebranded... absolute garbage), I've had nothing but trouble with it. I plan on swapping it out one of these days.