OK, I think I figured it out. You're seeing the effect of your code being in a continuous loop that you can't get out of easily.
Your formMenu has a timer event of 50, which is milliseconds. 1000 is one second, so this code is running every 0.050 second (I think):
Code:
If Not IsNull(DLookup("[data]", "cons_alarme")) Then
DoCmd.SetWarnings False
DoCmd.OpenForm "ALARMES"
DoCmd.OpenQuery "CONS_ALARME_DES"
DoCmd.SetWarnings True
End If
When you fix the timer duration values in code, it still may not run without errors - at least it didn't for me.
So much for my earlier comments...