Question : upgrading compatability level in SQL 2000

the server is in version 2000, but the Database CP is in 6.5.

Is there a lot of difference between the two? Would you think there should be testing before changing from 65 to 80 compatibility level or there should not be any issues?

thanks

Answer : upgrading compatability level in SQL 2000

testing is the correct word.

backup/restore the database to another db name or instance, and test the application with the changed CP