facebook and twitter doesn't open on wingate's clients

[behnam]

hi all

when my clients try to open facebook and twitter
this error appears for them :

The server at www.facebook.com is taking too long to respond.
The server at twitter.com is taking too long to respond.

what can i do for it.
thanks for your helps.

Behnam

[behnam]

for more explains

i live in iran and facebook and twitter are blocked by the government
in iran we use vpn or proxy for bypass these filtration
now i want give my clients non filtered internet so i use wingate(by upstream proxy).the http websites are good and they open fine(all of them,filtered and non filtered).https websites that have not been filtered are good to open like google.com but filtered https websites do not open(on clients)

i think these https websites need ssl connection to be open

what is your idea ?
how can you help me?

Behnam