CISCO Configuration register stuck at 0x3922 - bug CSCvh27335

- bug associated :  CSCvh27335
- multiple platforms affected
- incl. C800 series, C180x series 
- same issue also with Cisco ISR 2811
- changing confreg values doesn't work via ROMMON nor via config
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SOLUTION:

Change the console baud-rate to a default which is 9600.
After the reload a correct 0x2102 value would show up properly.

conf t
  line con 0
    speed 9600
do wr
do sh ver | s register

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MagLab-phys-R01(config-line)#do sh ver 
Cisco IOS Software, C180X Software (C180X-ADVENTERPRISEK9-M), Version 15.1(4)M12a, RELEASE SOFTWARE (fc1)

ROM: System Bootstrap, Version 12.3(8r)YH13, RELEASE SOFTWARE (fc1)

R01 uptime is 3 hours, 25 minutes
System image file is "flash:c180x.bin"
Last reload type: Normal Reload

Cisco 1802 (MPC8500) processor (revision 0x200) with 589824K/65536K bytes of memory.

9 FastEthernet interfaces
1 ISDN Basic Rate interface
1 ATM interface
1 Virtual Private Network (VPN) Module
250880K bytes of ATA CompactFlash (Read/Write)
Configuration register is 0x3922  <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<




 
MagLab-phys-R01#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
MagLab-phys-R01(config)#config-r
MagLab-phys-R01(config)#config-register 0x2102
MagLab-phys-R01(config)# do sh ver | s register
      
Configuration register is 0x3922

MagLab-phys-R01(config)#line con 0
MagLab-phys-R01(config-line)#speed 9600
MagLab-phys-R01(config-line)#do sh ver | s register
         
Configuration register is 0x3922 (will be 0x2102 at next reload)

MagLab-phys-R01(config-line)# -------------------------------------------------------------------------------------------------