thanks for you reply...
i replaced the layout and menu files but that didnt help...
so i started browsing the file system with FAR....turned out i had two files missing!
1) BG_IMAGE_STANDBY.@
2) BG_IMAGE_STANDBY.gif
so after putting those 2 files in my phone..i got my animated wallpaper back!!
i just dont get how those files went missing..