APP Market Fix:
1.Open the Market app (from the Home screen or app launcher)
2.Leaving the Market app running, return to the Home screen and open the Settings app again
2.Within Settings select Applications → Manage applications → Running (from Tab at top)
4.Scroll to select the Market app → press the Clear Cache button → then press the Force Stop button (Do not press the Clear Data button)
5.Press the back button (to go back to the list of running apps)
6.Scroll to select Google Services Framework → press the Clear Data button → OK (to confirm) → then press the Force Stop button
7.Return to the Home screen
8.Launch the Market app again, which will give an error "Attention an error has occurred..." → OK button
9.Shutdown by holding power button → Power Off → OK
10.Restart, wait for wi-fi to reconnect, open Market again (You may have to reboot several times and check Market)
The opening Market screen should no longer be blank, and many more apps (free & paid) should now be available. (Although apps can be downloaded, a few may still fail to install or run properly).

I pressed camera button but when settings i go Applications → Manage applications → Running there is not market app? Why? What i did wrong?