QWhen I try to erase a rewriteable CD, I get a "Power Calibration Error" that makes the disc unusable.

AStart with the simplest possible solution -- using a different brand of CD-RW. A lot of shoddy blank discs are out there, so see if your CD burner's manufacturer recommends any brands and use one of those. If that disc, fresh out of the wrapper, doesn't work, then the problem has to be in the CD-RW drive itself.

A firmware update can cure strange malfunctions in CD burners; if any firmware updates are available for yours, download and install them.

If that doesn't help, open the drive's tray and gently use a can of spray air (sold at electronics stores) to blow out any dust.

If none of those remedies work, replace the CD burner; new internal models go for $75 or less.

Can I be monitored by the recording industry if I share MP3 files on a free WiFi connection?

This reader is looking for a way to continue his file-sharing habits without becoming the target of a lawsuit by the Recording Industry Association of America. He's wondering if using an Internet connection that can't be traced to him would make his activities completely untraceable.

My answer is: You can't count on that. Do you know for sure that your file-sharing program doesn't allow you to be identified in other ways? What about any adware or spyware that was installed with it?

Plus, there's a practical angle: Just how much time do you plan to spend in the coffee shop or whatever business gives away its WiFi access? Will that business's owners be pleased to see you eating up that free bandwidth for hours on end with multi-megabyte downloads and uploads?

Sorry, but you're going to have to pony up to the bar and pay for your tunes.

-- John Gilroy

John Gilroy of Item Inc. is heard on WAMU's "The Computer Guys" at noon on the first Tuesday of the month. Send your questions to him in care of The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or via e-mail to jgilroy@iteminc.com.