Question: what is the difference of 2.4 and 2.6 kernel?
Answer: The biggest change to LKMs between Linux 2.4 and Linux 2.6 is an internal one: LKMs get loaded much differently. Most people won't see any difference except that the suffix on a file containing an LKM has changed, because they use high level tools to manage the LKMs and the interface to those tools hasn't changed.