addition: I deleted the mup.sys from the drivers and the dllcache directory, but it´s obviously not the reason for the failure to boot. When booting in safe mode, the mup.sys does not come up anymore in teh list of drivers loaded, but the system stalls anyhow.
Here are the last entries in the log:
/drv/ HypRealCpu.c:578 CPUs calibrating
/drv/ HypRealCpu.c:621 CPUs (2) TSC counter calibrating was successful (calibrate time 0 mksek)
00:17:08.913 F /vm:10188/ [Profile] Event Loop post-initialization time is 19 msecs
00:17:08.914 F /vm:10188/ [Profile] Event Loop Initialization time is 20 msecs
00:17:08.914 F /vm:10188/ Vm {d1c885f9-eff7-4a99-989f-84581853dcdc} processed command vmCmdStart with status 1
00:17:08.946 F /vm:10188/ [Profile] Post-Event Loop Initialization time is 31 msecs
00:17:08.951 F /vm:10188/ Event loop inited - launching
00:17:08.975 F /vm:10188/ Vm {d1c885f9-eff7-4a99-989f-84581853dcdc} processing command vmCmdInitiateDevStateNotifications ....
00:17:08.999 F /vm:10188/ Vm {d1c885f9-eff7-4a99-989f-84581853dcdc} processed command vmCmdInitiateDevStateNotifications with status 1
00:17:13.141 F /vm:10188/
[0]Chipset Type i815, 2 CPU(s) (NORTH HUB DID&VID=0x80861130)
[0]FirstStartInit is OK
[0][1f:0] Secondary bus number 0xff
00:21:07.912 F /vm:10188/ Vm {d1c885f9-eff7-4a99-989f-84581853dcdc} processing command vmCmdStop ....
00:21:07.923 F /vm:10188/ Vm {d1c885f9-eff7-4a99-989f-84581853dcdc} processed command vmCmdStop with status 1
00:21:08.552 F /vm:10188/ Vm {d1c885f9-eff7-4a99-989f-84581853dcdc} processing command vmCmdStop ....
00:21:08.565 F /vm:10188/ Vm {d1c885f9-eff7-4a99-989f-84581853dcdc} processed command vmCmdStop with status 1
00:21:08.587 F /vm:10188/ Vm {d1c885f9-eff7-4a99-989f-84581853dcdc} processing command vmCmdStop ....
00:21:08.605 F /vm:10188/ Setting ASYNC_REQ_SHUTDOWN for Vm
00:21:08.610 F /vm:10188/ Event loop terminated - deinited
00:21:08.612 F /vm:10188/
00:21:08.616 F /vm:10188/ [Devices] Terminating...
00:21:08.617 F /vm:10188/ [Profile] Networking termination time is 0 msecs
00:21:08.892 F /LocalDevices:10188/ [AppHDD] Disconnect
00:21:08.905 F /vm:10188/ [Profile] IDE device 0 termination time is 288 msecs
00:21:08.905 F /vm:10188/ [Profile] SCSI adapter termination time is 0 msecs
00:21:08.905 F /LocalDevices:10188/ [Floppy0] Terminating
00:21:08.906 F /LocalDevices:10188/ [Floppy0] Disconnecting
00:21:08.908 F /vm:10188/ [Profile] FDD 0 termination time is 3 msecs
00:21:08.908 F /vm:10188/ [Profile] FDD 1 termination time is 0 msecs
00:21:08.909 F /LocalDevices:10188/ [Parallel0] Terminating
00:21:08.909 F /LocalDevices:10188/ [Parallel0] Disconnecting
00:21:08.912 F /vm:10188/ [Profile] Parallels port 0 termination time is 3 msecs
00:21:08.912 F /LocalDevices:10188/ [CSoundDevice:

one] Sound output terminating...
00:21:08.913 F /vm:10188/ [Profile] Sound output termination time is 1 msecs
00:21:08.913 F /LocalDevices:10188/ [CSoundDevice:

one] Sound input terminating...
00:21:08.914 F /vm:10188/ [Profile] Sound input termination time is 1 msecs
00:21:08.918 F /vm:10188/ [Profile] USB controller termination time is 4 msecs
00:21:08.918 F /vm:10188/ [Profile] Power source termination time is 0 msecs
00:21:08.920 F /vm:10188/ [Profile] Tools dispatcher termination time is 1 msecs
00:21:08.920 F /vm:10188/ [Profile] PCI toolgate termination time is 0 msecs
00:21:08.927 F /vm:10188/ [Profile] PCI video termination time is 6 msecs
00:21:08.928 F /vm:10188/ [Profile] OTG dispatcher 3 termination time is 0 msecs
00:21:08.928 F /vm:10188/ [Profile] OTG request tracker termination time is 0 msecs
00:21:08.941 F /vm:10188/ [Profile] Device used thread termination time is 13 msecs
00:21:08.941 F /vm:10188/ [Devices] Terminating finished
00:21:08.942 F /vm:10188/ [Profile] Terminating time is 326 msecs
00:21:08.954 F /ioctl:10188/
/drv/ HypVtd.c:3321 [vtdOnMonitorQuit]
/drv/ HypVtd.c:1902 [vtdFreeDomain] Unknown domain, do nothing...
/mon/ [HpcMonitorClose] Close monitor
/drv/ HypVMManager.c:419 Monitor quited successfully
00:21:08.972 F /vm:10188/ VMFiniMemory completed successfully
00:21:08.974 F /vm:10188/ VM successfully stopped.
00:21:08.976 F /vm:10188/ Vm {d1c885f9-eff7-4a99-989f-84581853dcdc} processed command vmCmdStop with status 1
00:21:08.986 F /vm:10188/ [CMainThread::~CMainThread]