Upgrade 2000 to 2005 complaining about OLAP repository

[SQLWilts]

Hi,
I have windows 2003 64 bit itanium, sql server 2000 64 bit enterprise 2187 build on a named instance.

I am trying to upgrade to SQL 2005 itanium enterprise edn.

There is/was an installation of analysis services on this machine.

I insert the disc and get as far as selecting the database engine, but it is greyed out (I only select database services to upgrade earlier in the process - this is the stage where you tick the database services box just before it goes off and upgrades). when I select details to tell me why it is greyed out, I get:

Check for SQL Server a repository of Olap

OK, so I go into add/remove programs, click change on the SQL 2000 box, put a red X against analysis services, it appears to go through the motions, but afterwards analysis services is still there.

Does anyone have any idea as to how I can remove this repository, and therefore go ahead and upgrade to SQL 2005? Incidentally, upgrading the analysis services doesn't help either... tried that