problem adding memory Compaq Deskpro EN

Hi - I have a problem adding memory to my Compaq Deskpro EN - it had
one
128MB stick, I have just added a 256 MB stick. The Compaq configuration
record show "Compaq memory = 384Mb and Windows memory = 128Mb". Windows
system info shows 128Mb. The CMOS setting also show 128Mb and there
doesn't seem to be any way to change it. POST shows 128. Compaq memory
diagnostics see 384Mb and the memory tests
pass.

I tried swapping the sticks around - the system won't boot with the new
256 stick in the first slot - the bios just beeps at me (one short two
long + flash numlock = memory error).

I also tried upgrading the bios from 686P2 v2.11 to 686P2 v3.14 - no
joy.

I have a 1GHz Celeron CPU which I think is non-standard - maybe that
has something to do with it? I believe it has 100Mhz front side bus -
the memory I installed is PC133 V-Data - maybe it wont work at 100? The
128Mb stick which is working is Hyundai PC133U--333-542 Sync CL3
(whatever that means)

The CMOS config doesnt have an option to edit the meory settings so
I assume it supposed to auto-detect it. Actually now F10 doesn't do
anything - could that indicate a CMOS battery problem?

Crucial want much help - I ran their activeX checker and it said it
didnt recognize my system (the precise model I think).

Any suggestions?

BTW this is a repost of a message I putup a couple of days ago and then
deleted again since my email address was flapping in the breeze - sorry
about that...