The crash occurs every boot, or random? Which IE version are you using?
Are you willing to provide application crashdump? If so:
Register Dr. Watson as JIT debugger by command “drwtsn32.exe -i”
Run drwtsn32.exe without parameters and select “Full” crash dump type in Dr. Watson’s dialog.
After next crash of AvastEmUpdate.exe, please upload crash dump to ftp.avast.com “Incoming” folder, default path of crash dump file is C:\Documents and Settings\All Users\Application Data\Microsoft\Dr Watson\user.dmp