Antenna Problem

My problem is getting a good connection when I put my PC where I want it to
be.

Here is the list of hardware:
Netgear FM114P Wireless Firewall Printer Server
Old Pentium II 400 Mhz with No USB ports
Xterasys PCI Wireless Lan NIC XN-2511b

Other hardware:
HP Jornada 568
Linksys CompactFlash Wireless Card.

My FM114P is at one end of my apartment. I have my other computers here.
What I wanted to do is connect up an old PC in the living room. The distance
is about 50 feet.

With my Jornada and the Linksys card I had a few problem connecting. Then I
ran across the article about Deep Dish Cylindrical Parabolic reflectors. I
put one of those on the Netgear FM114P. Now in the living room with my
Journda I the link quality and signal strength are both over 80% and usually
close to 100%.

The Xterasys card is in the old PC. I added a Deep Dish Cylindrical
Parabolic reflector. Where the PC is sitting right now I have a link
quality and signal strength of almost 100%. What I want to do is move the
PC to the right about 6 inches and back about 2 feet. When I do that, the
link quality and signal strength drop to 0%. Currently there is a direct
line of sight between the antenna on the FM114P and the PC's antenna. At
this moment the PC is sitting in the doorway between the living room and the
dining room. I want to the PC 6 inches to the right. This puts a wall in
between the two antennas. There must be something in the wall that
interferes with the signal.

I thought about building a Cantenna, but it does seem to be a bit of an
overkill. If I keep the PC in the doorway, I have nearly perfect reception.
I want to move the PC less than three feet, but if I do that I have no
reception.

I played around with the antenna on the Xterasys card and the Netgear
FM114P. They have the same connector. I cannot move the FM114P. I have
other computers and a printer attached to it.

According to http://www.fulton.net.au/qt045.htm the FM114P has a Reverse SMA
connector. http://www.wimo.com sells a Reverse SMA plug to Reverse SMA jack,
RG-58 cable.

I really didn't want to spend much more on this project. I guess my question
is this: is it worth it to buy the Reverse SMA plug to Reverse SMA jack, to
move the antenna 3 feet or should I think about building an antenna like the
cantenna or the Tin Can Waveguide?

Jeffrey