I fixed this issue a while back by creating my owned signed driver using the driver files from the base Win 8.0 install. Doing this requires that Windows 8.1 be permanently run in test mode (TESTSIGNING ON), but besides putting a watermark on the desktop I haven't come across any issues with this. I know creating your own drivers isn't for everyone and it isn't something we shouldn't have to do but here are the instructions for anyone interested....
Reference article : http://msdn.microsoft.com/en-us/library/ff546236(v=vs.85).aspx
From C:\Program Files (x86)\Windows Kits\8.0\bin run the following commands in Administrator command prompt:
makecert -r -pe -ss PrivateCertStore -n CN=yourname.com(Test) c:\drvtest.cer
stampinf -f c:\drivers-w8\net1ic64.inf -d 09/20/2013 -v 12.6.47.2
Put the CatalogFile.NTAMD64 = net1ic64amd64.cat line in the inf file under [Version] section
Inf2cat.exe /driver:c:\Drivers-W8\ /os:8_X64
Signtool sign /v /s PrivateCertStore /n yourname.com(Test) /t http://timestamp.verisign.com/scripts/timstamp.dll c:\Drivers-W8\net1ic64amd64.cat
Bcdedit.exe -set TESTSIGNING ON
certmgr.exe /add c:\drvtest.cer /s /r localMachine root
Signtool verify /pa /v /c c:\drivers-w8\net1ic64amd64.cat c:\drivers-w8\net1ic64.inf
Signtool verify /pa /v c:\drivers-w8\net1ic64amd64.cat
Reboot PC (to activate Test Mode)
Install driver in Windows
To do the above you need a system with the Windows Driver Kit (WDK) 8.1 installed and obviously need the cat and inf (and sys) driver files from Windows 8.0 (base install) that I reference in the commands above.
Intel tried to help with this issue but got to a point where they couldn't continue unless I could supply a laptop for them to perform the troubleshooting on (which I couldn't from Australia) which is fair enough, and Lenovo have been totally useless. No response at all from them.
I hope this can be fixed properly at some point.