Maxell hopes to ship its new 4X DVD-R and 2X DVD-RW media in February. The 4X discs will support a transfer rate of about 5.5 megabytes per second, and the 2X discs, about 2.8 MBps--provided they're used with the corresponding drives for their speeds. As with CD-R and CD-RW, faster DVD-RW/-R drives won't operate at their optimum speed unless they sense that the discs inside them are up to it.

But the new media will have some compatibility problems. For example, it's likely that DVD-ROM drives and DVD players manufactured before this fall won't be able to read 4X DVD-Rs, acknowledges Rich Gadomski, Maxell representative.

Worse yet, writing to these discs may damage some older DVD-RW/-R drives, drive manufacturers have acknowledged. If you own an older drive, you should check with your drive manufacturer about a firmware upgrade (usually a free Internet download) to fix the problem. Pioneer Electronics, for example, warned customers about the possibility in October and urged firmware upgrades.

"You're not supposed to use 4X media in a 2X drive without getting a firmware upgrade to the drive," Gadomski says.