if the xeon responds to i2cdetect at 0x18 then using the adm1021 driver as documented in doc/chips/SUMMARY with modprobe adm1021 force_adm1021=0,0x18 shoud give you good results. adm1021 will report 2 temps, one will be invalid and the other is the real temp. Send us the results and the output of i2cdump 0 0x18 (assuming i2c is bus 0).