Declaring variables mid-function changes results

If I declare the variables x,y,z, and w at the top of the function, the results are correct. If I leave them where they are, the results are incorrect rotations. If I comment out the KeyHit() command or add a Delay(1) command, the results are correct. Any printing or debugging I do makes the results correct, and masks the problem.

I wish I could give a better example, but any changes I make hide the problem. Any idea why this could be?

	Method Rotation:TQuat()
		Rem
		Local sc:TVec3=Scale()
		Local iv:TVec3=Vec3(ix,iy,iz).Scale(1/sc.x)
		Local jv:TVec3=Vec3(jx,jy,jz).Scale(1/sc.y)
		Local kv:TVec3=Vec3(kx,ky,kz).Scale(1/sc.z)
		
		Local t#=iv.x+jv.y+kv.z+1
		If t>0
			t=Sqr(t)*2
			x=(kv.y-jv.z)/t
			y=(iv.z-kv.x)/t
			z=(jv.x-iv.y)/t
			w=t/4
		Else If iv.x>jv.y And iv.x>kv.z
			t=Sqr(iv.x-jv.y-kv.z+1)*2.0
			x=t/4
			y=(jv.x+iv.y)/t
			z=(iv.z+kv.x)/t
			w=(kv.y-jv.z)/t
		Else If jv.y>kv.z
			t=Sqr(jv.y-kv.z-iv.x+1)*2.0
			x=(jv.x+iv.y)/t
			y=t/4
			z=(kv.y+jv.z)/t
			w=(iv.z-kv.x)/t
		Else
			t=Sqr(kv.z-jv.y-iv.x+1)*2.0
			x=(iv.z+kv.x)/t
			y=(kv.y+jv.z)/t
			z=t/4
			w=(jv.x-iv.y)/t
		EndIf
		Return Quat( x,y,z,w )
		EndRem
		Local fourWSquaredMinus1:Float = +ix+jy+kz
		Local fourXSquaredMinus1:Float = +ix-jy-kz
		Local fourYSquaredMinus1:Float = +jy-ix-kz
		Local fourZSquaredMinus1:Float = +kz-ix-jy
		Local biggestIndex=0
		Local fourBiggestSquaredMinus1:Float=fourWSquaredMinus1
		If fourXSquaredMinus1 > fourBiggestSquaredMinus1
			fourBiggestSquaredMinus1 = fourXSquaredMinus1 
			biggestIndex=1
		EndIf
		If fourYSquaredMinus1 > fourBiggestSquaredMinus1
			fourBiggestSquaredMinus1 = fourYSquaredMinus1 
			biggestIndex=2
		EndIf
		If fourZSquaredMinus1 > fourBiggestSquaredMinus1
			fourBiggestSquaredMinus1 = fourZSquaredMinus1 
			biggestIndex=3
		EndIf
		Local biggestValue:Float=Sqr(fourBiggestSquaredMinus1+1.0)*0.5
		Local mult:Float=0.25/biggestValue
		Local x#,y#,z#,w#
		Select BiggestIndex
			Case 0
				w#=BiggestValue
				x#=(jz-ky)*mult
				y#=-(kx-iz)*mult
				z#=-(iy-jx)*mult
			Case 1
				x#=-BiggestValue
				w#=-( jz - ky )*mult
				y#=( iy + jx )*mult
				z#=( kx + iz )*mult
			Case 2
				y#=BiggestValue
				w#=-(kx-iz)*mult
				x#=-(iy+jx)*mult
				z#=(jz+ky)*mult
			Case 3
				z#=-BiggestValue
				w#=(iy-jx)*mult
				x#=(kx+iz)*mult
				y#=-(jz+ky)*mult
		EndSelect
		'If KeyHit(KEY_L) Notify BiggestIndex
		Return quat(-x,y,z,w)

		
		
		Rem
		'testing code:
		Global mode=0
		If KeyHit(KEY_N)
			mode:+1
			'Notify mode
		EndIf
		If KeyHit(KEY_L) Notify mode
		Select mode		
			Case 0 Return quat(x,y,z,w)
			Case 1 Return quat(x,y,z,-w)
			Case 2 Return quat(x,-y,z,w)
			Case 3 Return quat(x,y,-z,w)
			Case 4 Return quat(-x,-y,z,w)
			Case 5 Return quat(x,-y,-z,w)
			Case 6 Return quat(-x,y,z,w)
		EndSelect
		EndRem
		
	EndMethod