Unresolved symbol error in __wake_up_sync

[sudharsan vijayaraghavan]

Hi
    We wrote a module in which we used wake_up_interruptible,
wake_up_interruptible_sync calls and when I compiled it into a      
module
with the appropriate Macros, it gets compiled properly.
 	But once, when I try to load the module with insmod, I get
__wake_up_sync -  unresolved symbol?
 	What module should I load to get out this error? I am using
2.4.7-10.

Please help us out.

Regards,
Sudharsan.