FPL doesn't identify socks or http proxies. It save all the proxies leeched in "proxy.txt".
If you leeched the socks proxy pages, you should test them with a socks proxy tester and vice versa.
Before testing, you should remove the duplicates in "proxy.txt". The build-in tester Bleach can do that easily, but it can only test http proxies.
BTW, thanks for your notice of Emetrix's problem. I'll contact them ASAP.