@sinbad yeah, and if I remember rightly, DOS/Windows at least tells you when it's doing memcheck stuff?
Sure this isn't the first time she's booted that device since the clocks changed a couple weeks ago? And sure it didn't start happening after the previous change? If it's set to GMT instead of BST then that'd be causing a skew for 6 months every year, and I've seen those cause short boot hangs waiting for a time dependant daemon to give up and return execution. Granted not normally so early.