Error: Exceeded Maximum Number Of Bytes Per Row

Hello, I received an error while attempting to create a table similar to the following...

CREATE TABLE ExampleTable (
[FIELD_0] [int] IDENTITY(1,1) NOT NULL,
[FIELD_1] [nvarchar](255) NULL,
[FIELD_2] [nvarchar](255) NULL,
[FIELD_3] [nvarchar](255) NULL,
[FIELD_4] [datetime] NULL,
[FIELD_5] [nvarchar](255) NULL,
[FIELD_6] [nvarchar](255) NULL,
[FIELD_7] [nvarchar](255) NULL,
[FIELD_8] [nvarchar](255) NULL,
[FIELD_9] [nvarchar](255) NULL,
[FIELD_10] [nvarchar](255) NULL,
[FIELD_11] [nvarchar](255) NULL,
[FIELD_12] [nvarchar](255) NULL,
[FIELD_13] [nvarchar](255) NULL,
[FIELD_14] [nvarchar](255) NULL,
[FIELD_15] [nvarchar](255) NULL,
[FIELD_16] [nvarchar](255) NULL,
[FIELD_17] [nvarchar](255) NULL,
[FIELD_18] [nvarchar](255) NULL,
[FIELD_19] [nvarchar](255) NULL,
[FIELD_20] [nvarchar](255) NULL,
[FIELD_21] [nvarchar](255) NULL,
[FIELD_22] [nvarchar](255) NULL,
[FIELD_23] [nvarchar](255) NULL,
[FIELD_24] [nvarchar](255) NULL,
[FIELD_25] [nvarchar](255) NULL,
[FIELD_26] [nvarchar](255) NULL,
[FIELD_27] [nvarchar](255) NULL
)

First of all, field names have been changed to protect the innocent. Second, I did *not* create this table...I'm troubleshooting issues with a previously created table. I've no idea why almost every field needs to be an NVARCHAR data type of that size. Finally, as you can probably guess, I'm getting this error on a SQL Server 2000 database. (Yeah, it's past time we upgraded to SQL Server 2005 at least...explain that to management, please. I suggest you speak slowly and use small words.)

Anyhow, the error is "Warning: The table 'ExampleTable' has been created but its maximum row size (13348) exceeds the maximum number of bytes per row (8060). INSERT or UPDATE of a row in this table will fail if the resulting row length exceeds 8060 bytes."

Am I misunderstanding how the row size is calculated? How is SQL Server getting 13,348 bytes from the above statement?

Any and all constructive suggestions/ideas are much appreciated! Thanks!