Hi Matt,
Good points by the others, especially about the possibility that other wireless devices may be competing for bandwidth. If you haven't already, try turning off all other devices in the house that may be wirelessly communicating with the router, or else putting them on the 5 GHz band if possible. For that matter, try turning off all wireless devices in the house that may utilize the 2.4 GHz band, regardless of what they may be communicating with.
Also, try changing the wireless channel that is being used, within the 2.4 GHz band. The manual for the router should explain how to do that.
Also, try disabling encryption if it is presently enabled.
Regarding wireless-G compatibility with 96 kHz/24 bit/2 channel music data, if that is what you are trying to play, the corresponding rate for the music data itself is 4.608 megabits per second. Error detection and correction information, packet headers, control words, encryption, and packet retries when and if needed, all consume bandwidth in addition to that. An optimally functioning wireless-G link, IME, will typically provide rates in the 12 to 20 mbps area, which should be adequate. But there isn't a great deal of margin to accommodate bandwidth competition, RF interference, or less than optimal performance by any of the hardware that is involved.
A point of information regarding one of the earlier comments: If a wireless-G device, such as the Squeezebox, is connected to a wireless-N router, the speed with which the router communicates with other wireless-N devices will not slow down to wireless-G rates. It will communicate with other N devices at N rates, while communicating with G devices at G rates. Although of course the G device will tie up the network for a greater amount of time than it would if a given amount of data were communicated at N rates. N is different in that respect than wireless-G, where the presence of a slower wireless-B device will cause all communications on the network to slow to B speeds.
Regards,
-- Al