e1000.ko: -1 Invalid module format

[Sendhilraj T <Sendhilraj.T@xxxxxxxxxxxx>]

Hello ,
I am writing a e1000 network driver on a 2.6.18.2-34-default.
When I give insmod I get the following error
e1000.ko: -1 Invalid module format.

when i give dmesg -c I get the follwing message
e1000: disagrees about version of symbol struct_module
can any one help me to get rid of these errors?
Do I need to change anything in make file?

looking for your help.

Senthil