Bad modem.. get rid of it.
Lock channel to 3 or 8, don't worry about overlap, you SHOULD NOT BE USING WIRELESS FOR ALL YOUR CONNECTIONS ANYWAY, your speed locks to your slowest device....
And in router setup, youshould be able to select 1 to 11 or "AUTO" which turns on the undesireable scan feature
This has been solved, tuirned out to be partially user error (myself), I got the clue
after browsing through the user manual
It turns out that when channel bandwidth is set to "auto", only wireless channels 1-7
are available. To pick between 1 - 11, you must first set channel bandwith manually
I am going to try Ms Raye's suggestion of locking on ch 8 to see ifI get a consistent
connection. Wi-Fi is not my only access, I have a wired desktop, which works fine.