Rich:fileUpload não funciona!

<rich:fileUpload fileUploadListener="#{fileUploadBean.upload}"			                     
							      id="upload"							     
							      acceptedTypes="jpg, gif, png, bmp" allowFlash="#{fileUploadBean.useFlash}">
				<a4j:support event="onuploadcomplete" reRender="info,tipoIntimacaoList,upload,intimacaoList,pnl,intimacaoSearch,checkBox,resolverIntimacao" />
</rich:fileUpload>

public void upload(UploadEvent event){  

        String diretorio = "C://DocumentosComprobatorios//";
    	
        try {
        	UploadItem item = event.getUploadItem();  
        	ByteArrayOutputStream b = new ByteArrayOutputStream();  
        	b.write(item.getData());  
        	//File file = new File();  
			b.writeTo(new FileOutputStream(diretorio+item.getFileName()));
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}  
    }