Can it be upgraded?
Is that in ToB?

------------------
"No!" shreiked Tyrion. Though the sword felt heavy as a fallen tree he lifted it. He saw the deamon look up, astonished. He brought down the blade with the awesome majestic power of a falling thunderbolt. The burning blade caught the deamon right in the centre of its forehead. The deamon's head fell apart under the force of the impact. The deamon N'kari sank to its knees, dead.

-Tyrion at the battle of the Blighted Isle.
Right now he is mourning for USA.

it can be upgraded in SOA and then again in TOB

I dont think the mace is upgraded in TOB , there is a another weapon of disruption though which can be though.

------------------
Hear no evil, speak no evil
See no evil, feel no evil
Dream no evil, fear no evil
Touch no evil, taste no evil
All I see and hear is evil
All I think and feel is evil

SPOILER
.
.
.
.
.
.
.
.
.
.
.
.
The Mace of Disruption can be upgraded with some pure illithium. You get this as part of one of the Temple quests (I think its Lathlander). Cromwell the dwarf in the Docks section can use both to upgrade the Mace.

first do geust of unseeing eye than talk to a
man in tempel he give you guest

------------------
http://www.geocities.com/waverider1478be/aerie.jpg
am proud to be a Platinum Spell Jammer of ALSB

you dont have to actually finish the unseeing eye quest. once youve agreed to do it, the other priest will give you the sarles/illithium quest.