When you open your world, you need to wait for the maps loading in item frames to see their content. I have maps in my home and don't need to wait for "loading" when I enter my bedroom. So, this is a bug.
Environment
Java Version 7 Update 40
Microsoft Windows XP Service Pack 3
NVIDIA GeForce 8400 GS revision 2 PCI Express released in december 4 2007
Intel Celeron 430 1.8 GHz 1 core 65nm LGA775 FSB 80MHz released in june 2007
2 memory units of 1GB DDR2 SDRAM maximum in transfer rate 6400MB/s
54000rpm Samsung hard disk HD502HI SATA 3.5"
I was uncertain if it was duplicate or not, so I created this other issue.