for client version Lightstreamer Silverlight Client Library version 1.1.3537.25900 user only can poll instead of stream. There is no proxy involved, here is the log entry

15.Apr.10 13:05:40,563 < INFO> Serving request: /lightstreamer/create_session.tx
t?LS_user=3931be67-a465-46c9-ae19-c25d7460ab16&LS_adapter_set=SAdapter&LS_con
tent_length=50000000&LS_polling=true&LS_polling_mi llis=0&LS_idle_millis=30000&LS
_report_info=true from 10.35.185.113:41159
15.Apr.10 13:05:40,565 < INFO> Starting new session: S78c524cd6a396481T0540564 from 10.35.185.113:41159
15.Apr.10 13:05:40,739 < INFO> Serving request: /lightstreamer/control.txt?LS_session=S78c524cd6a396481T0540564&L S_op=add&LS_table=1&LS_id=S_ADAPTER&LS_mode=RAW&LS _schema=MESSAGEID+DATA+MESSAGE_TS&LS_data_adapter= S_ADAPTER from 10.35.185.113:41159
15.Apr.10 13:05:40,739 < INFO> Controlling session: S78c524cd6a396481T0540564 fr
om 10.35.185.113:41159
15.Apr.10 13:06:10,898 < INFO> Polling (2) to session: S78c524cd6a396481T0540564
from 10.35.185.113:41159

Thanks.