Just opened the link you gave and...
"For example, a 1500 byte packet, the largest allowed by Ethernet at the network layer (and hence most of the Internet)"
... ehhh? I know for testing that 1500 or less is working about perfectly, is this why i'm having so much trouble?

Last tests i had now weeks ago had issues when i was downloading something same time. The whole thing seemed like a mess that i couldn't understand. WSockets itself i went through carefully and it is simple enough to know where things are going and what it does.