Strangely enough, I seem to be experiencing the same problem on my current test install...
2008-08-05 02:18:34 : <KTD> KTD will not be applied, the DriverPacks will be deleted.
2008-08-05 02:20:13 : <CLNP> Could not delete the DriverPacks, which are located in "C:\D".
2008-08-05 02:20:13 : <CLNP> Added new value to the RunOnce key in the registry: the cleanup of the "C:\D" directory will be retried (through CLI, not through the Finisher) after a reboot.
2008-08-05 02:20:13 : <CLNP> Deleted "C:\hwids.dat"!
2008-08-05 02:20:13 : <CLNP> Deleted "C:\DPsFnshr.ini"!
2008-08-05 02:20:13 : <CLNP> Deleted "C:\devcon.exe"!
2008-08-05 02:20:14 : <CLNP> Deleted "C:\makePNF.exe"!
2008-08-05 02:20:14 : <CLNP> Deleted "C:\pmtimer.exe"!
2008-08-05 02:20:15 : <CLNP> Deleted "C:\*.ins"!
2008-08-05 02:20:15 : <CLNP> Deleted "C:\DSPdsblr.exe"!
2008-08-05 02:20:16 : <CLNP> Deleted "C:\DriverPack_*.ini"!
2008-08-05 02:20:16 : <CLNP> Deleted "C:\mute.exe"!
2008-08-05 02:20:16 : <CLNP> Added new value to the RunOnce key in the registry: the DriverPacks Finisher itself will get deleted after the next reboot.
2008-08-05 02:20:16 : Program terminated.
D folder still present even after two reboots.
Never happended before and I did not deviate from my ususal settings at all!
The stuff on %systemroot% got all deleted, though...