My only guess is something either entered the camera view that is causing rendering problems, or something left the camera view that prevented the rendering problems. I suggest paying careful attention to what else might be different between the two scenarios.
@Monster, yes. if i move the mouse on the other side. the scene goes back to normal,same with moving backward.
But when the character goes back to that position, it all turns into BLUE.Sir, What do you think is the problem?
@Kupoman, i already checked the scene, it has only terain,houses and overlayed scene for the HUD.
blend files needs to go through each intermediate version for correct conversion:
2.49 -> 2.5x+save -> 2.60+save -> 2.61+save
Just from seeing I wonder if
A) the camera is showing something complete different.
B) the objects disappeared from render (obvious they still exist and work).
A) parent a cube to the camera that you can see it all the time. Then test again. Does the Cube disappear too?
B) switch to wireframe mode. Do the objects still disappear? GSLS->Multitexture?
Look from Side view/top View etc.?