Daniel,

It seems that I'm able to unset the password and then can use any of the special characters except for !, that results in the following error:

sw15(config)#enable password Example!

Command not found / Incomplete command. Use ? to list commands.

Which is odd, because I was able to use ! before flashing to the new firmware.  I'm currently on this version:  

sw15#show version

Machine Description............... Dell Networking Switch

System Model ID................... N3048

Machine Type...................... Dell Networking N3048

Serial Number..................... LOTSOFCHARACTERSHERE0000x000

Manufacturer...................... 0xbc00

Burned In MAC Address............. Z0MG.N0WA.I11!

System Object ID.................. 1.3.6.1.4.1.674.10895.3058

SOC Version....................... BCM56340_A0

HW Version........................ 5

CPLD Version...................... 13

unit active      backup      current-active next-active

---- ----------- ----------- -------------- --------------

1    6.1.0.6     6.2.0.5     6.1.0.6        6.1.0.6

Regards!