Elusivo Landar

when i use my normal cable internet connection, everything works fine, hours without a crash or disconnection, but when i use my same cable internet connection using a vpn connection then i can log in to sl, but after a minute or two my avatar can't walk anymore, then a few seconds later can't chat, and a few secs more i crash... Is there a fix to enable the use of vpns with sl? btw, i have tried a lot of other diferent online games and services and they all work flawlessly through the vpn, just secondlife fails