access db 2003 has an upper limit when i want the last record it go to number 610

thanks for replay this is the function i use to display the last record ,its archive application
so i need to know the last record that i entered yesterday
after i save the record i use this to take its id so i can use it as a name for the page i get by
the scanner

static string str = "provider=microsoft.jet.oledb.4.0;data source=" + Application.StartupPath + "\\scti.mdb";
OleDbConnection con = new OleDbConnection(str);
OleDbDataAdapter dataadapter3;
DataSet dataset3 = new DataSet();
<pre lang="cs">private void get_idtext()
{
textBox8.DataBindings.Clear();
string sid = "select idnum from received";
dataadapter3 = new OleDbDataAdapter(sid, con);
try
{
con.Open();
dataadapter3.Fill(dataset3, "received");
con.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
this.BindingContext[dataset3, "received"].Position = this.BindingContext[dataset3, "received"].Count - 1;
textBox8.DataBindings.Add("text", dataset3, "received.idnum");
}</pre>

yes there are many deleted records but the code (as i understand)take the existing records from the table and put it in dataset3 and go to the last record ,also it was work correctly for tow months
when i open the db by access i found about 29 records after 610 so i deleted the record 610
the result was that the application considered the 609 as the last record?????
is there any relation between the autonumber and the Count?