It seems to me that the wifi-module of a tablet started to receive a signal at bigger distance from a signal source (wifi-router) after firmware installation.
Before firmware installation the tablet received a signal from a router in radius about 7 meters (about 10 meters after installation - from the first room through two walls of an adjacent room to the third room).

And still for me there is one unresolved problem. I can't find the answer how to connect an android-tablet to the cell phone, using wifi-connection (phone is connected to the Internet) to receive on a tablet Internet access through this cell phone (? Ad-hok connection?).
My laptop (windows xp) easily finds this point of access (phone as a wifi-router) and is connected thus to the cell phone. The tablet doesn't find this point of access.
I read somewhere that Android doesn't support such connection.

Somebody knows, whether there is a way of the solution of this problem?