Hi, I've previously mailed this to the equivalent udf mailing lsi but had no response - maybe I'm asking in the wrong place :-( I have built 2.4.19-pre7, updated with udf 0.9.6 from sourceforge and patched with packet-2.4.91-pre4.patch made by Peter Osterlund. udf and pktcdvd are compiled into kernel rather than as modules (although I've also built with these as modules and it makes no difference). When I try to format a rewritable disk I get the following: #cdrwtool -d /dev/hdc -t 2 -q using device /dev/hdc setting speed to 2 1600kb internal buffer setting write speed to 2x setting for /dev/hdc Fixed packets, size 32 Mode-2 disc I'm going to do a quick setup of /dev/hdc... Initiating quick disc blank wait-cmd: Input/Output error Command failed: 51 00 00 00 00 00 00 00 02 00 00 00 - sense 02.04.07 read disc info: Illegal seek can't unlock door #dmesg shows: VFS: Disk change detected on device ide1(22,0) cdrom: This disc doesn't have any tracks I recognize! hdc: packet command error: status=0x51 { DriveReady SeekComplete Error } hdc: packet command error: error=0x50 ATAPI device hdc: Error: Illegal request -- (Sense key=0x05) Command sequence error -- (asc=0x2c, ascq=0x00) The failed "Prevent/Allow Medium Removal" packet command was: "1e 00 00 00 00 00 00 00 00 00 00 00 " hdc: packet command error: status=0x51 { DriveReady SeekComplete Error } hdc: packet command error: error=0x50 ATAPI device hdc: Error: Illegal request -- (Sense key=0x05) Command sequence error -- (asc=0x2c, ascq=0x00) The failed "Prevent/Allow Medium Removal" packet command was: "1e 00 00 00 00 00 00 00 00 00 00 00 " Exactly the same error occurs if I leave out the -t 2 argument. H/W config is: AMD K6-III+ @550MHz FIC VA503+ Mobo with 256MB RAM /dev/hda is 40GB HDD - single partition with Win98SE on /dev/hdb is DVD drive /dev/hdc is Mitsumi CR-4802TE CDRW drive /dev/hdd is 8.4GB HDD partitioned as 8GB Linux Ext3, 128MB Linux swap and remainder as a FAT32 partition which I share between Win and Linux I am using cdrwtool from udftools-1.0.0b2. I'm out of my depth now so would be grateful for any advice about how I can fix this. Thanks in advance. Chris --- This message has been virus checked by Grisoft AVG during dispatch. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.351 / Virus Database: 197 - Release Date: 19/04/02