differences between 2000 and 2005?

we are experiencing poor performance on a 2005 database. to date much of what we have worked with has been 2000. i am suspicious that some of the parameters we set when we run the DDL to create the database may be a problem. can anyone comment on any of the paraemeter below and whether they might cause an issue in 2005? Many thanks.
EXEC sp_dboption N'ABC', N'autoclose', N'false'
GO
EXEC sp_dboption N'ABC', N'bulkcopy', N'false'
GO
EXEC sp_dboption N'ABC', N'trunc. log', N'false'
GO
EXEC sp_dboption N'ABC', N'torn page detection', N'true'
GO
EXEC sp_dboption N'ABC', N'read only', N'false'
GO
EXEC sp_dboption N'ABC', N'dbo use', N'false'
GO
EXEC sp_dboption N'ABC', N'single', N'false'
GO
EXEC sp_dboption N'ABC', N'autoshrink', N'false'
GO
EXEC sp_dboption N'ABC', N'ANSI null default', N'false'
GO
EXEC sp_dboption N'ABC', N'recursive triggers', N'false'
GO
EXEC sp_dboption N'ABC', N'ANSI nulls', N'false'
GO
EXEC sp_dboption N'ABC', N'concat null yields null', N'false'
GO
EXEC sp_dboption N'ABC', N'cursor close on commit', N'false'
GO
EXEC sp_dboption N'ABC', N'default to local cursor', N'false'
GO
EXEC sp_dboption N'ABC', N'quoted identifier', N'false'
GO
EXEC sp_dboption N'ABC', N'ANSI warnings', N'false'
GO
EXEC sp_dboption N'ABC', N'auto create statistics', N'true'
GO
EXEC sp_dboption N'ABC', N'auto update statistics', N'true'
GO

if( ( (@@microsoftversion / power(2, 24) = 8) and (@@microsoftversion & 0xffff >= 724) ) or ( (@@microsoftversion / power(2, 24) = 7) and (@@microsoftversion & 0xffff >= 1082) ) )
EXEC sp_dboption N'ABC', N'db chaining', N'false'
GO
USE ABC
GO
EXEC sp_configure 'show advanced options', 1
GO
reconfigure with override
EXEC sp_configure 'max degree of parallelism', 1
GO

Thanks for your response. This is a 2005 database on SP2. We actually migrated to 2005 from Oracle recently. We are seeing some timeouts on connections. Still trying to determine what exactly is going on.