I have exactly the same problem since the latest kernel update with my Kubuntu gutsy installation:
kernel [ 2185.818660] device-mapper: table: 254:1: linear: dm-linear: Device lookup failed
25.11.2007 11:40:34 zalas kernel [ 2185.819148] device-mapper: ioctl: error adding target to table
I didn't have this problem before. How can I stop the process. My kubuntu installation is unusable right now.