I had a mexican creme guava that lasted 2 winters
(in New Orleans 9B)
But this last winter was unusually cold. it got down to 25F for 2 nights in a row and that killed it.
at least i think its dead. it lost every leaf, and no new growth yet.

I dont know much about mango's. i think they are a little hardier, at least when mature.

I beleive Mango's need full sun, and guava do better in full sun, but can handle part shade.

im not an expert on either though,
the link may help with your guava...

Here is a link that might be useful: gardenweb Guava

Sorry about your guava. Hope it comes back when the weather gets warm.

We ended up planting both close to a north facing concrete wall about 15' from each other so they don't shade each other. They will get summer sun almost all day because the sun travels east to west.

Currently, the wall shades them, but when they grow taller, they should be fine. In the same row, there is a queen palm, and a hibiscus, and both of those are in full sun.

Fingers crossed!

Thanks for the link!