What is rebuffering?

My Squeezebox is connected wirelessly to my router. I use Rhapsody for background listening on my Squeezebox. Periodically a song will stop right in the middle of playing for about ten to fifteen seconds and start playing again. That's annoying as hell.....especially when I'm singing along. I check the screen on the Squeezebox and it says that the song is 'rebuffering'. What does that mean? Do you think that if I went wired instead of wireless that the dropouts would stop? My Squeezebox is 50 ft away from the router and I have one of those super double-speed whiz-bang wireless N routers.
Rebuffering is caused by the interruption of wireless signal. Wireless communication isn't as reliable as wired connection so using wired connection should eliminate the problem. If it doesn't than there is something wrong with your Squeezebox.

You can also try the followings:

1. Change the setting in the wireless router to operate in a different channel.

2. Move the wireless router away from Microwave oven and cordless phone to reduce interference.

3. Upgrade wireless router firmware to the latest version.

4. Although you have a "N" router, Squeezebox doesn't use the new "N" standard. It operates in the older "g" standard which is less immune to noise and has a shorter range than the "N" standard. You can buy another N router and configure it as a WiFi to Ethernet bridge (note, not all WiFi router can be configured this way, one I know that can is the Apple Extreme Base Station). You than connect the ethernet bridge to the Squeezebox with a wire and let the bridge communicate with your existing "N" router thought wireless in the "N" standard.
Just a quick reminder that your local network (wired or wireless) is not the only possible source of transmission delay. The problem could be occurring due to delays at Rhapsody's end, your ISP's or somewhere in between those two. There have certainly been many times over the years when I've waited longer than normal for a web page to load due to some burp in the network outside my home.
Sidssp has good recomendations.

Devices like the Squeezebox and Roku Sounbridge have an onboard memory buffer or cache that is used to store bits in advance of the time at which they are needed downstream by the DAC so they do not have to be received in -real time.

Rebuffing means the bits are not arriving over the wireless connection fast enough to keep the music playing.

Its commonly due to a weak wireless connection but not always. Sometimes it can be that the source is not able to put the bits out fast enough due to demand or other technical issues.

Most likely in your case its the wireless connection speed, which is good because you have control over that and not over the Rhapsody source. Try to get the router closer to the Squuezebox if possible and also look to see if there are any solid objects in the line of sight between router and box that might obstruct the signal. REposition to avoid obstructions if possible. Metal ductwork hidden behind drywall, metal appliances and such can be the culprits.
One quick question - do you use your Squeezebox to also play music that has been saved on your computer? If so, a wireless connectivity problem will also cause interruptions with that.

If music stored on your computer plays OK and only the Rhapsody suffers interruptions, then the cause is likely outside your home network.

Your original question only mentioned a problem with Rhapsody.

If both suffer interruptions, then you can start looking at your in-home network. You've received some good suggestions for improvements if that's the issue.
If you have problems with a computer as the source, de-fragment the disk on the computer periodically to keep those bits flowing faster and check to see if there are any programs running in the background that can be stopped so that more resources are available to serve up the music.
You guys are great, thanks to all of you for your advice and suggestions. There is enough stuff in your posts that you guys have suggested to assure me that I can remedy this thing one way or another.

Yes, there are solid objects in the line of sight between the router and Squeezebox, and for aesthetic reasons, that cannot be changed.

I haven't played much music from my hard drive lately on my Squeezebox, but I'll check it out to see if I get the same dropouts. I do have a 100 ft cable to run along the wall on the floor to get a wired connection, and it won't be much of a problem to do so...I just wanted to go wireless because the technology allowed it.