I have found a solution to my problem. I still could not get the bubble sort to work, so I created my own, that takes no more time to run then the bubble sort. I'll post in case it helps anyone.
Private Function SortFsChartRow(collection As collection) As collection
Dim min As Integer
Dim max As Integer
Dim x As Integer
Dim y As Integer
Dim rowCurr As FsChartRow
Dim numCurr As Integer
Dim rowMin As FsChartRow
Dim rowMax As FsChartRow
Dim search As Integer
Dim sorted As collection
Set sorted = New collection
min = 100
max = 0
For x = 1 To collection.count
Set rowCurr = collection(x)
numCurr = GetNumeric(rowCurr.label)
If numCurr > max Then
max = numCurr
Set rowMax = rowCurr
End If
If numCurr < min Then
min = numCurr
Set rowMin = rowCurr
End If
Next x
search = min
For y = 0 To max
For x = 1 To collection.count
Set rowCurr = collection(x)
numCurr = GetNumeric(rowCurr.label)
If numCurr = search Then
sorted.Add rowCurr
Exit For
End If
Next
search = search + 1
Next y
Set SortFsChartRow = sorted
End Function