scanemal.dll error

have p4 with xpsp2 as os. use microsoft outlook as my email client connected to exchange server 5.5. have mcafee antivirus v4.5.1 sp1.
as i open msoutlook i get error “scanemal.dll” and im not able to check mails or do anything. but at the same time word,excel is working fine.

when i uninstall antivirus or xpsp2 its working fine. also its also works fine with when i uninstall antivirus.
what may be the resolution. help pls.