FileUpload still showing buttons

[f2pro]

Hello, I'm using PrimeFaces 3.0 M4 and the component fileUpload has the following configuration:

<p:fileUpload fileUploadListener="#{cadastroPessoasMB.envia}"
mode="advanced"
sizeLimit="3000000"
fileLimit="1"
auto="false"
update="tab:img_example"
allowTypes="/(\.|\/)(gif|jpe?g|png)$/"
cancelLabel="Cancelar"
invalidFileMessage="Arquivo Inválido"
invalidSizeMessage="Insira uma imagem menor de 3Mb"
label="Procurar"
showButtons="false"
oncomplete="alteraImagem.hide()"/>

Note that I put "showButtons = false" but it still showing the buttons uload, cancel and chose.
I tried to remove the options cancelLabel, label but it didn't work, I tried too copy the sabe example that has in the primefaces's site but didn't worked.