Originally posted by kgb
2. create all the tablespaces existing in the old database with datafile sizes 50% bigger than the original one.

WHAT THE POINT OF IT ???

I always do that and it always works:
1. Create a blank database.
2. Create RBS tablespace, the same as you have in your a dump file.
3. Create TEMP tablespace.
4. Restart database.
5. Import with options: full=y commit=y feedback=1000
Thanks to all who responded, as the above worked fine for me.