Dear Friends

I have some db problem with Firebird 2.1 beta 1 the same as last
1. first i now have very good hardware with ECC ram
2. NO any power fail and restart With good UPS !
3. also force write is ON (yes ON)
4.and i do not merge any DDL and DML


but still see in validation :
"Number of index page error : 3"

this need backup , restore to resolve this problem

what mean ?
and also this mean data coruption ?
and also how this error ocurs ?