I'm having lots of TX (transmit) errors.
Try setting the ACK Timing to 0. If you have the transmit power turned up higher than 84 mW, turn it down to 84 mW. Other things that may contribute to a lower error rate: set beacon interval lower than the default of 100 (75, for example), use a different channel (aka frequency) for wireless (so not to clash with other 2.4 GHz devices). Use a better antenna than the stock antenna your device comes with, this actually helps you more than increasing output power as this option increases both output and sensitivity at the same time.
 How high should I set the transmit power on my router?
Somewhere around 84 mW is considered to be the best setting for maximum power with minimum noise for most hardware. The Buffalo WHR-HP-G54 has a built-in amplifier. The amplifier is turned on by default; the radio power should not be set above 10mW (on v23SP2), or 70mW (on v24). The forums have had discussions about what power level is safe, with little consensus. Use common sense and don't set the power higher than you really need to. If you're trying to get more range, consider using a different antenna and make sure you have a clear line of sight, two of the most critical factors in your router's range.
From a network security standpoint, the transmitter power level should be just enough to cover the intended area reliably. Optimal power settings can be determined by trial-and-error.
 How can I increase my wireless range?
Many factors affect your range. What method you use to extend your range will depend on whether you are trying to increase the range inside a building or outside. Read the next two FAQs below.
Consider getting a good antenna and try setting up your wireless devices with a clear line of sight. Best range is achieved by using one directional parabolic dish or Yagi antenna and then disabling the other antenna on your router. For a cheap easy antenna option, try www.freeantennas.com
. This site details how to make a directional antenna from household items which can result in 10 db or more in gain. For situations where you need omnidirectional distance instead of directional linking, be sure to use a good omnidirectional antenna and mount it high enough to broadcast signal in the area of focus. This is often 20 to 50 feet high, depending on the rated signal downturn of the antenna. This means how steep of an angle the donut of radiated signal is pitched down from the vertically-mounted antenna.
Also, try increasing your router's transmit power to 84 mW (unless you have a Buffalo with a built-in amplifier). DD-WRT also has settings for frame burst and afterburner. You may see an increase in range by turning these off. If you are mostly interested in Internet access, then 802.11b (as opposed to 802.11g) has longer range and may actually give you faster Internet speeds in long-range, low-signal situations.
Note: If you are using encrypted communication such as WPA, you can not use "802.11b Only" mode with WDS. If you are using unencrypted communication, "802.11b Only" mode will work for WDS. WPA encryption via WDS will only work if "Mixed" or "802.11 g Only" modes are set for WDS. "WPA Pre-shared Key" with "AES" encryption is the only currently known WPA encryption model to work with WDS setup.