If the range extender has an aerial that you can reposition, try it so that the aerial is transmitting on the same plane. By that I mean, with my AP downstairs and my M1001 upstairs, moving the aerial so that is was nearer the horizontal greatly improved signal strength and stability.
I had problems with an M1001 when it had low signal strength. It generally failed to get a dhcp address.
Out of interest, have you tried setting your M1001 to use a fixed IP address ? I wonder what the dhcp lease time is ?
Thanks for your post. Can I just clarify re the aerials, they are currently both vertical, are you suggesting moving them both to be horizontal?
To be honest, I didn’t think it was a signal strength issue as the wireless quality is showing at 98. However, I am interested in the fixed IP address suggestion. Can you advise how to do this?