First of all ... It wouldn't let me post this under MCPE 0.8.1. Can an admin/mod please copy this to the correct location? Sorry... Project drop down only gave 3 options: Minecraft, Minecraft API, Scrolls. No option for MCPE. Affects versions drop down only gave me MC PC options... no idea why.

ANYWAY, the bug:

I am playing on my creative map. My friend who is at my house on my wi-fi logs in to my world. As soon as the world loads up immediately he sees that something is wrong. From his device only, it looks like a new seed has been generated on top of my world. The terrain takes on unusual and unnatural looking characteristics. There are areas with deep fissures. There are flat areas littered with 1x1 columns of biome blocks. On the guest device, some parts of the map are correct, but mostly not. Many structures appear to be missing, buried, or replaced with other blocks.

Using iExplorer, I copied the world folder to the guest's phone, so that we could isolate whether it was a problem with the device. We tried again to play together but this time with the host and guest devices switched. We had the exact same problem just on the opposite devices. I was able to log in to one of his worlds as a guest and it appeared to be correct, so therefore it can be deduced that the issue is with one of the files pertaining only to that particular world with the issue.