Hello! I have done a program running with hsqldb and everything goes perfect.

Now I am running it with MySQL and the program fails in every query referenced to a particular table in the database. This table contains one object Calendar, one object Hashtable and the rest are simple Strings. The error is "could not deserialize". The rest of the queries that refers to the other tables goes perfect.
I have proven these three dialects:

#hibernate.dialect org.hibernate.dialect.MySQLDialect
#hibernate.dialect org.hibernate.dialect.MySQLInnoDBDialect
#hibernate.dialect org.hibernate.dialect.MySQLMyISAMDialect

How can I solve this problem??

Thank you very much.