solution: kernel 2.6.7 or lower (i personally have shifted to 2.4.27 b/c i find 2.6.8 & .10 rather unstable with my snd-card & ide times out too often ) or do not use k3b.
If it's a kernel problem then other burning software also shud not be able to detect writers. In fedora core 3 none of them detected my LG cd writer. On googling I found that u have to place a cd in the writer for it to get detected (atleast for my LG )
Pankaj