WPA supplicant reconnect with wireless often (but not always) needs reboot of router and/or computer

[Edmond Rodriguez]

Without providing logs or versions (I have kept up to date), I wonder
if there are any obvious possible answers for the following problem.

Supplicant almost always works when (using WPA) ( using -Dwext  and I
am running ndiswrapper):
  - both computer and router are freshly booted.

BUT does not work:
  - If I disconnect and reconnect, often I have to reboot my router
and also often my machine to make it work again.   Yes, I do exit or
kill all wpa processes on the machine and I have also tried clearing
retained information from dhcpcd (though I don't think that matters).
I also try completely removing the ndiswrapper module and reloading
that.   I just can't connect again unless I reboot the machine and
often the router as well.  Sometimes just rebooting the router works,
but usually I have to reboot the machine as well.    This does not
happen when I try using wireless with XP.  With XP I never have to
reboot the router or the machine.

For testing and diagnostic purposes iwconfig (no encryption) always
works (with ndiswrapper as well).

Any obvious clue what is going on?