Unable to calculate tex size

Hello,

I need some help here. It's a rather complex problem but I'll try to explain. On some computers I get the error "Unable to calculate tex size" too. Unfortunatly not no my PC, so it's hard to debug.

It's in the AdjustPixmap code in TTexture.bmx
The code I show you below is from Klepto and it's posted in a post I did for another problem (see: http://www.blitzbasic.com/Community/posts.php?topic=72501#811490)

	Function AdjustPixmap:TPixmap(pixmap:TPixmap)
	
		' adjust width and height size to next biggest power of 2 size
		Local width=Pow2Size(pixmap.width)
		Local height=Pow2Size(pixmap.height)

		' check that width and height size are valid (not too big)
		Repeat
			Local t
			glTexImage2D GL_PROXY_TEXTURE_2D,0,4,width,height,0,GL_RGBA,GL_UNSIGNED_BYTE,Null
			glGetTexLevelParameteriv GL_PROXY_TEXTURE_2D,0,GL_TEXTURE_WIDTH,Varptr t
			If t Exit
			If width=1 And height=1 RuntimeError "Unable to calculate tex size"
			
			If width>1 width:/2
			If height>1 height:/2
		Forever

		' if width or height have changed then resize pixmap
		If width<>pixmap.width Or height<>pixmap.height
			pixmap=ResizePixmap(pixmap,width,height)
		EndIf
		
		' return pixmap
		Return pixmap
		
	End Function

The problem should lie in the two lines:

			glTexImage2D GL_PROXY_TEXTURE_2D,0,4,width,height,0,GL_RGBA,GL_UNSIGNED_BYTE,Null
			glGetTexLevelParameteriv GL_PROXY_TEXTURE_2D,0,GL_TEXTURE_WIDTH,Varptr t

It seems there is a possibility the pixmap is interpreted wrong on some systems. I checked if the (intergrated) graphics cards have OpenGL support.
Are there more specific OpenGL-compatibilities I have to check for, or is this a software problem that can be solved?

PS: I tried different colour depths:
Graphics3D 1024, 768, 32, 1
Graphics3D 1024, 768, 16, 1
Graphics3D 1024, 768, 0, 1
with no results.

<edit>
Replaced the AdjustPixmap() function with the remarked version in TTexture:

	Function AdjustPixmap:TPixmap(pixmap:TPixmap)
	
		Local width=Pow2Size(pixmap.width)
		Local height=Pow2Size(pixmap.height)

		If width<>pixmap.width Or height<>pixmap.height
			pixmap=ResizePixmap(pixmap,width,height)
		EndIf
		
		Return pixmap
		
	End Function

and that solved the problem. I'm happy with that for now (there's a user test comming up next week so I was in desperate need of a working version) but I'd like to now what is going on. Klepto2... any ideas?