When you use "route print" (without OpenVPN running), do you see any routing table entries involving the 10.5.x.x sub-net? If not, then this is not an issue.
I have one more suggestion. Add this to the OpenVPN config file:route-nopull route 0.0.0.0 126.96.36.199 route 188.8.131.52 184.108.40.206 route 10.5.0.1 dhcp-option DNS 10.5.0.1
This will set up routes exactly like the default, except that new entries for 127.0.0.1 (the "local host" address) will not be set up. These entries are not needed, since 127.0.0.1 is provided as a local interface internally by Windows (or any other OS). On my machine these entries do not cause an issue. But maybe they are on yours for some reason, so that you are losing connectivity to the Tore.exe SOCKS proxy interface.
I tried it, but nothing changed.
When I use "route print" I don't see any entry involving 10.5.x.x subnet, so I must deduct that this is not the problem.
I'm out of solutions then... sad...
You said that you can use OpenVPN by itself. Did you you try this with TCP on port 443? Or just UDP? Using TCP 443 without Tor will use the same 10.5.*.* subnet. And most of the routing table stuff will be the same. If this will not work, try another TCP port without Tor to see if any of them work:
If you find one that works, then try that over Tor.