i can download v8.0.65.0 but each time i do so i recive this message upon scanning;before i install it.(i havent)

Warning: AntiVirus engine for IFO returned [File Corrupted] on [******\ZAZA_SETUP_EN.EXE]

i have no accelerator i know off and have tried both mozzlia and as suggested i.e. still no joy.
if i download 7.0.483.000 or any pervious version i have no issiue.

i have the above installed alought when i manually or auto check for a update it tells me there is none.
i did once and i updated to the first v8 release,until i relised it was currupted then rolled back to v7,since installing that version again i now as said get told my system is upto date.

am i secure with this version installed?
how can i update if i keep getting downloading currupted files.

i hazzard a guess v7 downloads ok as it is a straight download and i dont have to use the zaSetup_en.exe installer to download v8 (i hope you understand what i mean there)

i do have spysweeper with av installed is this causeing my problem?
are they not compatabile?

i see it doesnt play nice but i dont know fully what that means i can guess but i am not sure if having this installed is my problem,i do have a acer comp but its not a vista os its xp with all the updates installed.

thank you for any freely given time to this subject.

Operating System:Windows XP Home Edition
Software Version:7.0
Product Name:ZoneAlarm (Free)