Row Looks to be blank but its not

[bremen22]

I have a workbook that I use to reformat data from its original format into the format I want.

In that workbook there is a macro that deletes all of the blank rows on the main sheet

Sub delblankrows()

Dim s1 As Worksheet
Dim tmpR As Range
Dim rowcount As Long, colcount As Long, i As Long, j As Long, k As Boolean

'Change "Sheet1" to the name of your worksheet.
Set s1 = Sheets("sheet1")
Set tmpR = s1.UsedRange
rowcount = tmpR.Rows.Count
colcount = tmpR.Columns.Count

'Starts from bottom row and looks for non-empty cells from left to right.
'Moves to row above if non-empty cell is found.
'If none is found, then deletes row and shifts values up.
For i = rowcount To 1 Step -1
    k = 0
    For j = 1 To colcount
        If tmpR.Value2(i, j) <> "" Then
            k = 1
            Exit For
        End If
    Next j

I have used this line of code in numerous other sheets and it works fine. In this book, however, there are rows that appear empty but when I run the macro those do not get deleted.

When I select the row and "clear contents" and run the macro again the row gets deleted.

I dont even know where to start figuring this one out....