What versions of ePO, ePO agent and VirusScan are you using?
The only certified version of VirusScan for Win8 is 8.8 Patch 3, and you need a minimum of ePO Agent 4.6 Patch 1 and ePO 4.5 (see KB74593 )
Another thing to consider is that IE 11 Metro (Win 8) does NOT support plugins. I don't know if this has been remedied or not; see http://www.eightforums.com/windows-8-news/3539-metro-style-internet-explorer-10- ditches-flash-plugins.html (the article is a year old.)
In pre RTM and RTM Gold releases of Windows 8, I had problems pushing to the systems due to firewall issues. Try turning off the Windows firewall service and see if that makes a difference.