A few days ago, I fixed the most annoying bug in the configuration of my Dell Latitude 6430u. Now for the next one:
Occasionally, my Windows 7 freezes (it isn't even possible to move the mouse cursor) - sometimes the systm recovers abter half a minute or such, sometimes it doesn't. In the event log, a "The device, \Device\Ide\iaStor0, did not respond within the timeout period" error appears.
To fix this, I found two suggestions: disabling the "Aggressive Link State Power Management" in the power management's advanced section, and disabling the "Intel Link Power Management" with a registry hack (see this parameters explaination):
Windows Registry Editor Version 5.00

I don't know which of these two solutions actually fixed the problem, but I already spent too much time here, so I won't investigate any further...