The 1.12 StatusBar widget runs into problems when you start using very large numbers for min and max values, like what oCB does when your system uptime gets too high. The workaround is to use some fixed boundary like SetMinMaxValues(1, 100) and update SetValue with the time passed since oCB.startTime as a percentage of 100.
Fix for oCB2:
http://pastebin.com/GntmzrPaFix for oCB3 (latest):
http://pastebin.com/j5muruYqReplace your ...Interface\AddOns\oCB\casting.lua with the appropriate fixed version of casting.lua.