Hola Mayra,
Voy a traducir tu problema por los demas. Tambien, te sugiero que escribes en un nuevo asunto aqui en este foro o en el foro en español. Es porque este asunto es de un otro theme (se llama "Discuss").
Tambien, cuales versiones del theme y de Moodle usas? Necesitamos esa informacion para que podemos ayudarte mas. Las dos versiones de Zebra ya no estan probados en IE. La version mas nueva de Zebra no puede estar usado en IE porque usa mucho CSS3.
Oh! Saludos de Mexico!
Traduccion:
I'm translating Mayra's message earlier for you guys that don't speak Spanish.
"I am from Columbia...and I don't know much english... sorry... I have a problem with the Zebra Theme... it's that in older versions of IE like 7 or 8, the blocks look bad... in the image below, the left part is what it should look like... and the right part is what happens with the problem... I hope that you can collaborate with me. I appreciate you guys a bunch."
I informed her in the first part that she will get better response posting a separate topic about the problem either here in the themes forum or in the Spanish moodle forums. I also told her that both versions of the theme she is asking about (Zebra) aren't tested in IE (at least, that's what the discussion page says). The newest one uses CSS3, and so would be difficult to use in older version of IE anyways.
Edit: added info on IE