SQL Server 2005 and MSDTC use

Hi All, 

We have MSDTC installed as a Clustered resource in SQL Server 2005 environment. I know MSDTC is used for cross-database and distributed transactions.

I wanted to know:
1. Even if there are no distributed transactions, I heard there is a known issue with SQL 2005 Database engine which enlists(makes use of) MSDTC. Is this true and when?

2. We are going to implement DB mirroring. What has to be considered with regards to how MSDTC is used in case of Disaster recovery? Will there be any transactions mismatch etc?

Thanks, 
Regards,

Mandar