Model : TL-WR941ND

Hardware Version : V5

Firmware Version : 140627

ISP :

My problem is this:
I have a main WRT54GL router, which sits at the end of the house and who's signal all but disappears at the other end of the house.
I've upgraded it's antennas to 9dbi, this helped a bit (now I have some signal everywhere) but not enough, as when I'm far away I have very low speeds and occasional disconnects.
I've decided to add a TL-WR941ND as a wireless AP/extender to increase my wifi strength.
I've configure it to be a WLAN bridge (via this FAQ: http://www.tp-link.com.de/article/?faqid=440)
My network looks like this:
Modem---WRT54GL- wifi-TL-WR941ND- wifi-MyPCs/Smartphones

It all works fine at first, but every couple of hours it disconnects.
I've tried setting both routers on the same SSID, or different ones - same result.
I've tries working on different channels - it doesn't work, and the routers need to interconnect, so they need to be on the same channel.
The DHCP is currently set on WRT54GL (as this is what the procedure recommends), the TL-WR941ND is set with a static IP (outside the DHCP range).
During the disconnects I can connect wirelessly to TL-WR941ND, but cannot access it's management IP.
Neither can I access it from WRT54GL.
I can access it connecting locally (via a network cable), but the settings all look OK.
The only thing that seems to fix the issue is restarting TL-WR941ND, either via the power button or via the "reboot" menu.


I've browsed through the forums here looking for a solution.
I saw many people have had the same issue, unfortunately they either were unable to solve it, or solved it but did not post the solution they found.
There was this thread that seems to have solved it: http://forum.tp-link.com/showthread.php?1960-WR941ND-Intenet-Connection-Loss
But I have no idea what he meant under "While I had put it in at the beginning the separate menu for the DCHP also needed set.", and I'm not even sure he ha exactly the same problem as me.

Any help would be appreciated.

Thanks,
Alex