CRM 3.0 redeployment: setup has detected a version mismatch between specified database and the current product

well....its a new day....let's start from the beginning i had a CRM 3.0 installation previously....for some reason, i want to redeploy the CRM 3.0 using the older database.

1. my Active Directory is new (not back up new...it's just new, new). it has same name and users as in the previous installation.
2. installed the SQL server and restored the MSCRM and METABASE databases.
3. i have installed the CRMRedeployment tool and did exactly what is written in the redeployment manual.
4. when try to install in the diagnostic test the setup gives error under Microsoft SQL server.

   setup has detected a version mismatch between specified database and the current product

i have checked the net for resolution but no good. still i got a number of post in different forums and blogs about the same problem. one of the links is Microsoft community. one guy here says that he did solved the problem but does not say how. he gives hint though that it has something to do with the build version in SQL server. as usual i've got no clue about what he wants to mean? another link is Microsoft Dynamics CRM newsgroup. it has a some sort of resolution. but i cannot say whether it will resolve my problem or not? it is about upgrading from CRM 1.2 to CRM 3.0. let's what happens?