Issues with transparent https proxy and windows 8 updates

Hello,

i'm getting Update-Errors 80240440 unter "Windows 8 Pro x64" with activated transparent http(s) proxy.

These errors are gone, when i disable httpS-Scan and create a packetfilter rule (internal ---> HTTPS ---> any v4).

I already installed the proxy CA certificate into my browser (IE 10) as root ca, this wont help.

What can i do? Anyone else with this issue?

Firmware is the actual 9.004 (soft release)!