I have the Panasonic CW-7502 SCSI CDROM drive, with an AMD K6-2 350 and 128Mb of PC100 memory.
I have compiled the kernel, watch updatedb start running in the middle of a burn and compiled the Mercury compiler (much more memory, cpu and disk intensive then the kernel) during CD burns without any hitches. I do remember that on my old Cyrix P200 system with a TEAC CD-Writer, that it didn't like reading straight from the IDE CD-ROM to burn onto the SCSI CD-Writer. Since I use my CD-W as my only CD ROM now, I can't confirm if that is still true. Pete.