Why is this DX function so SLOW?

Hi, here is what I use to make my animation in my DX game. But it SLOWS down my game a LOT. Does anybody know whats wrong.

THanks.

Private Sub tmrEXP_Timer()

Dim t As Long

t = Timer

Do
DoEvents

Call DD_CreateSurfFromFile(App.Path & "\exp1.bmp", Expanim, BackBufDesc, 36, 42)

Loop Until Timer > t + 0.1

Call DD_CreateSurfFromFile(App.Path & "\exp2.bmp", Expanim, BackBufDesc, 36, 42)

Do
DoEvents
Loop Until Timer > t + 0.2

Call DD_CreateSurfFromFile(App.Path & "\exp3.bmp", Expanim, BackBufDesc, 36, 42)

Do
DoEvents
Loop Until Timer > t + 0.3

Call DD_CreateSurfFromFile(App.Path & "\exp3.bmp", Expanim, BackBufDesc, 36, 42)

Do
DoEvents
Loop Until Timer > t + 0.4
End Sub

How about loading all the surfaces at the start and then blitting the individual pieces down.
File access is kind of slow (for real-time graphics that is!)