app runs correctly only with debug

Thanks for the advice regarding the While loop. However as you expected it didn´t solve the problem.
I will post the complete code below so that anyone can try it out.

Global canw
Global canh
Global t
Global balmax

Type Ball
	Field x#,y#
	Field dx#,dy#
	Field size
	Field tt
	Field r,g,b
End Type


window=CreateWindow("Particle Engine",50,50,700,600)
CreateLabel("Number of particles",ClientWidth(window)/2-140,ClientHeight(window)-30,100,20,window)
textfield1=CreateTextArea(ClientWidth(window)/2-25,ClientHeight(window)-30,50,20,window)
button1=CreateButton("Ok",ClientWidth(window)/2+50,ClientHeight(window)-30,20,20,window)

UpdateWindowMenu window ; This MUST be called after creating your menu!
canvas = CreateCanvas (0, 0, ClientWidth (window), 500, window)
SetGadgetLayout canvas, 1, 1, 1, 1 ; Use zero to leave an edge 'unpinned'...

canh=GadgetHeight(canvas)
canw=GadgetWidth(canvas)

; MAKE BUFFER
SetBuffer CanvasBuffer(canvas)
done=False
timer=CreateTimer(25)
t=0 ;globale variabele om na enige tijd bal te verwijderen
balmax=100 ;maximum aantal ballen of particles

InitBalls(b.ball,balmax)

While done=False
	WaitEvent()
	Select EventID()
	Case $101 ; EventID keydown
		Delete_Balls(b.ball)
		t=0
		InitBalls(b.ball,balmax)
	Case $401 ;EventID gadget action
		If EventSource()=button1 Then ;verander het aantal ballen naar de textfield waarde
		;Stop
			;SetStatusText(window,Str(balmax))
			balmax=TextAreaText(textfield1)
			;Stop
		
		End If
		
	Case $803 ;EventID window close.
		done=True
	Case $2001	;suspend deze applicatie
		While WaitEvent()<>$2002
		Wend
	Case $4001 ; EventID checks when timer is timed out
		Cls
		Place_Ball(b.ball)
		Move_Ball(b.ball)
		FlipCanvas canvas
		t=t+1
		FlushEvents $4001
	End Select
Wend
End


;**************************************** FUNCTIONS *****************************************



Function Create_Ball(b.ball,x#,y#,dx#,dy#,size,tt,r,g,bb)
	b.ball=New Ball
	b\x=x#
	b\y=y#
	b\dx=dx#
	b\dy=dy#
	b\size=size
	b\tt=tt
	b\r=r
	b\g=g
	b\b=bb
End Function

Function InitBalls(b.ball,balmax)
	For i=1 To balmax
		x#=canw/2+Rnd(-5,5)
		y#=canh/2+Rnd(-5,5)
		dx#=Rnd(-5,5)
		dy#=Rnd(-5,5)
		size=Rnd(2,10)
		tt=Rnd(50,200)
		Create_Ball(b.ball,x#,y#,dx#,dy#,size,tt,Rnd(200,255),Rnd(150,200),Rnd(0,10))
	Next
End Function


Function Place_Ball(b.ball)
	For b.ball=Each Ball
		Color b\r,b\g,0
		Oval b\x,b\y,b\size,b\size,1
	Next
End Function

Function Move_Ball(b.ball)
	For b.ball=Each Ball
		b\x=b\x+b\dx
		b\y=b\y+b\dy
		If b\tt<t Then
			Delete b.ball
		End If
	Next
End Function

Function Delete_Balls(b.ball)
	For b.ball=Each Ball
		Delete b
	Next
End Function