Well, i didn't changed anything particular to the standard emule connection settings, i only reduced the max number of connections (to 500). In azureus i set the "Slowly connect to new peers - For people with internet disconnection issues", but it has no results.
1.7 firmware (oleg's also) still drops connection, 1.6 works ok! It must be something with the base code of the firmware, it's not something that oleg changed.

I'm now testing 1.7.5.9 firmware version that i saw in another post in this forum. I will post the results later.

Regards.