jQuery Grid Plugin - jqGrid

I have a jqGrid to get around 600 records from database.

It skip some pages when I click on pager navigation bar.

I tired to take out some fields from dataset then it skips less pages.

It does not skip any pages when I have the dataset only return one column, primary key.

I think that the data have some similary to let jqGrid skip pages.

I would like to know are there any way to set unique index for dataset that jqGrid does not skip pages when user scroll the records,

Your help and information is great appreciated,

Regards,

Iccsi,