I would suggest wait for about 3-5 minutes..... of late even mine is acting rather strange and it is taking 4-5 minutes to boot. It just shows the nokia screen and then nothing happens for a long long time.... after maybe 4 minutes the blue line starts to run across the screen and tehen the hands join with the nokia sound. I wanted to update to the latest firmware(sdhc bug fixed one) but i will hold on until the official firmware is realased and flash it without restoring the back up....
hope this helps