It's not a problem. The ECU watches the temperature of the transmission fluid, which slightly changes some shift points while the transmission fluid is cold. It also affects when it can use overdrive. Yes, this is normal. Here's an old thread in this forum where multiple people say the same thing:
http://www.4x4wire.com/forums/showflat.php?Cat=&Board=UBB13&Number=95611

Jeff
2000 4Runner SR5, supercharger, rear e-locker, ARB front locker, 285/75R16 MT/R's, custom bumpers & skids
2007 Tacoma double cab 4x4 - stock