Why do buildings appear and disappear at different magnifications?

Some of the large buildings I added disappear when I zoom in; and some buildings only show up at one zoom level. Even stranger some buildings on one block only show up at like the 3rd highest zoom level and some buildings on the block across the street only show up at the 2nd highest zoom level.

Has anyone else this problem? Is it a problem with my browser or am I doing something wrong when I add the buildings. Thanks for any tips, ideas, pointers, etc

I am now up to two pages of edits :) I added like 4 parks and a bunch of building and some schools. Man this is really fun.

PS
Does anyone know how to designate a building as a home or apartment?

Hi.

This is my first day on open street maps. I am not sure what people write in this diaries but here is a short bio.

My name is jon and I am a geology student at PSU. I found out about this site from my gis course. So far I really like it. This site is like finding out about wikipedia for the first time. So far I have been adding local stores, bars, etc that are around me. I hope to add more stores and improve my current entries. I will hopefully post more diary entries as I work more on the site.

ttfn
jon