Trouble with sortItems coercion of text in QTableWidget

[wconstan]

I am using Qt Creator 1.2.92 based on Qt 4.6.0 32-bit.

I'd like to develop a private slot to check each item of a QTableWidget to ensure that the item is (1) a "number" and (2) that the number is on the range (0,1). In the case that either of these tests fail, I would like to set the item to some specified coerced value. The code I wrote to do so is as follows:

void myProject::formatTimingTable()
{
    int i;
    int j;
    int nrow = ui->timing_tableWidget->rowCount();
    int ncol = ui->timing_tableWidget->columnCount();
    QString val;
    QTableWidgetItem *item, *itemReplace;
 
    for (i = 0; i < nrow; i++)
    {
        for (j = 0; j < ncol; j++)
        {
           item = ui->timing_tableWidget->item(i, j);
 
            // ensure item is not NULL
            if ( !item )
                continue;
 
            val = item->text();
 
            if (val <= "0"){
                itemReplace = new QTableWidgetItem("0.0001");
                ui->timing_tableWidget->setItem(i, j, itemReplace);
            }
 
            if (val >= "1"){
                itemReplace = new QTableWidgetItem("0.9999");
                ui->timing_tableWidget->setItem(i, j, itemReplace);
            }
        }
    }
 
    ui->timing_tableWidget->sortItems(0, Qt::AscendingOrder);
}

void myProject::formatTimingTable()
{
    int i;
    int j;
    int nrow = ui->timing_tableWidget->rowCount();
    int ncol = ui->timing_tableWidget->columnCount();
    QString val;
    QTableWidgetItem *item, *itemReplace;

    for (i = 0; i < nrow; i++)
    {
        for (j = 0; j < ncol; j++)
        {
           item = ui->timing_tableWidget->item(i, j);

            // ensure item is not NULL
            if ( !item )
                continue;

            val = item->text();

            if (val <= "0"){
                itemReplace = new QTableWidgetItem("0.0001");
                ui->timing_tableWidget->setItem(i, j, itemReplace);
            }
            
            if (val >= "1"){
                itemReplace = new QTableWidgetItem("0.9999");
                ui->timing_tableWidget->setItem(i, j, itemReplace);
            }
        }
    }

    ui->timing_tableWidget->sortItems(0, Qt::AscendingOrder);
}

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This scheme works but the sortItems function can sometimes coerce a "0.0001" entry to "0". For example,

1. When I run the associated app and enter a "0" in the first row of the table I get the result as shown in the attached firstZeroEntry.jpg file. In this case, the scheme works as planned.
   
2. If, however, I then enter a "0" in the second row of the table I get the result shown in the attached secondZeroEntry.jpg file. In this case, the item in the first row is set to "0".
   
3. If I then enter "0.4" in the third row of the table, I get the result shown in the third attached thirdZeroEntry.jpg file. In this case, the first and second row contain the correct "0.0001" entry.

I have confirmed that the issue lies with sortItems function because when I comment the corresponding sort line in the code each "0" entry is suitably replaced by "0.0001" regardless of the the entry/row in the table.

While I'm not entirely enthused by this whole approach in general, I am a bit confused as to why sortItems is coercing entries as described. Am I missing something?

Secondly, is there an easier way to do all this? Suggestions/comments welcome.

Finally, I realize that ncol = 1 (always) in my case. I could adapt the code accordingly...but that is another issue.

Thanks!