[acuartero]

Sounds like your database was created with a different block size. I believe the default under windows is 8K. You can do the following instead but for performance reasons it would be better to rebuild the DB with a 16k block size in the first place. I guess if its not going to be a production instance you can get away with this.

from the Admin guide... pg 3-19

This script creates LOB tablespaces with 16 KB block size. This is the recommended block size for
optimal performance. In order to create a tablespace with 16 KB block size, you should have the
following init.ora parameter set if your database standard block size is not 16 KB. Change the cache
size as needed for your database.
db_16k_cache_size = 104857600 # 100MB for 16k block buffers