Sir,

->Configaration:- Intel 845GVSR main board, Pentium 4 2.0A
Ghz, 256 MB DDR Ram, 40GB Samsung Puma HDD, 1.44 FDD,
Samsung 52x CDROM, LG 48X CDRW, Kobian ATX cabinet with
300watt SMPS. HDD is in Primary Master, CDROM in secondary
slave and CDRW is in secondary master position. OS is
Windows 98 SE

->Everything is ok but somtimes when i am trying to access
both CDROM & CDRW then one(either rom or writer) of device
is not functioning. After restarting the pc it works fine.
I have tested almost every individual sub systems on an
another PC all its works fine. The problem is
inconsistant. When there is only one optical drive(either
Rom or RW) the system works fine.

-> I have changed the Ribbon cable, SMPS(300watt instead
of 280watt) but problem persists.

I have upgraded the BIOS from VA84510A.86A.0023.P10 to
VA84510A.86A.0030.P10  but still the problem persists.  
BIOS detected the the two optical drives but windows
sometimes did not. I had wrote about the configaration of
my system and what i have done. Please give me some
logical and technical by  which i can shoot the trouble.
Wheather it is a problem of DMA?

->Can you help me ? I can not understand wheather its a
power problem or problem of a sub system or software
problem?