[klaus]

Erel,
This behaviour looks strange.

I renamed PrevBtn to PrevBtn1
I added a new button named it PrevBtn
Deleted button PrevBtn1
Renamed Sub PrevBtn1 back to Sub PrevBtn
And it works normally. Source QuestionExampleNew
in this code when PrevBtn.Enabled=False is executed,
the Radio_Click routine is not called.

I also tried the following code
in this code when PrevBtn.Enabled=False is executed,
the Sender in the Radio_Click routine is RadioButton1

Sub ShowData
  Label1.Text="Q"&(AnsRec+1)&". "
  If Answer(AnsRec)=0 Then
    For i=1 To 5
      Control("RadioBtn"&i).Checked=False
    Next
  Else
  Control("RadioBtn"&Answer(AnsRec)).Checked=True
  End If
  If AnsRec=0 Then
    PrevBtn.Enabled=False
    NextBtn.Enabled=True
  Else If AnsRec=5 Then
    PrevBtn.Enabled=True
    NextBtn.Enabled=False
  Else
    PrevBtn.Enabled=True
    NextBtn.Enabled=True
  End If
End Sub

instead of

Sub ShowData
  If AnsRec=0 Then
    PrevBtn.Enabled=False
    NextBtn.Enabled=True
  Else If AnsRec=5 Then
    PrevBtn.Enabled=True
    NextBtn.Enabled=False
  Else
    PrevBtn.Enabled=True
    NextBtn.Enabled=True
  End If
  Label1.Text="Q"&(AnsRec+1)&". "
  If Answer(AnsRec)=0 Then
    For i=1 To 5
      Control("RadioBtn"&i).Checked=False
    Next
  Else
  Control("RadioBtn"&Answer(AnsRec)).Checked=True
  End If
End Sub

in this code when PrevBtn.Enabled=False is executed,
the Sender in the Radio_Click routine is RadioButton2 which gives the wrong information.

Best regards