ExcelBanter - Weird WindowsMediaPlayer behaviour

So I had the following commands as part of a macro

Application.Cells(1, 1) = WindowsMediaPlayer1.Controls.currentPosition
Application.Cells(1, 2) = WindowsMediaPlayer2.Controls.currentPosition
Application.Cells(1, 3) = WindowsMediaPlayer3.Controls.currentPosition

which used to write the current position of the media player to cells a2, b1
and c1

Suddenly they resolutely show 0

The change I made was from

WindowsMediaPlayer1.URL = "c:\video\file1.wav"
WindowsMediaPlayer2.URL = "c:\video\file1a.wav"
WindowsMediaPlayer3.URL = "c:\video\file1a.wav"

to

WindowsMediaPlayer1.URL = "c:\video\file" & Range("a4") & ".wav"
WindowsMediaPlayer2.URL = "c:\video\file" & Range("a4") & "a.wav"
WindowsMediaPlayer3.URL = "c:\video\file" & Range("a4") & "a.wav"

where Range("a4") = 1

Even when I changed the code back it just wouldn't work.
Office 2007
Totally stumped. Suggestions welcome...