Not able to Add Asset to Tax book

Hello Experts,

The client has been live on 11i for about 10 years.  Now they want to start using tax books. I created a new tax book, ran initial mass copy. However, I noticed several assets did not get copied over to tax book. The assets are not expensed, not CIP, and not retired. They are capitalized.

1) Why did those assets did not get copied?

2) Also, the system is not allowing me to add them manually to tax (I am not allowed to save those assets in tax book).