I have just installed SQL 2005 CTP on a mchine with SQL 2000. As a
consequence both MSOLAP.2 and MSOLAP.3 providers are registered.

If I create a udl file and fire up the Data Link Properties dialog, Select
the MSOLAP.3 provider listed as "Microsoft OLE DB Provider for Analysis
Services 9.0" and connect to the Adventure works sample database all appears
well. A test connection succeeds. However when I exit from the dialog and
then re-open the link I find that the selected provider is "Microsoft OLE DB
Provider for Analysis Services 8.0". Looking into the datalink the registered
provider is MSOLAP.2

This would appear to be a bug?

Hard to say.

There are known issues with msolap.1 and msolap.2, where if you install
certain products on the same in a certain order msolap.1 becomes the
default driver, even though msolap.2 is present. This may be a similar
issue.

Try re-registering msolap90.dll by running this command:
regsvr32 "c:\program files\common files\system\oledb\msolap90.dll"

That should reset msolap.3 as the default provider

--
Regards
Darren Gosbell [MCSD]
<dgosbell_at_yahoo_dot_com>
Blog: http://www.geekswithblogs.net/darrengosbell