Here are some basic doubts that i have. I installed the following profile on a sdcard

I succesfully boot from sdcard
Booting from mmc ...
## Booting kernel from Legacy Image at 82000000 ...
   Image Name:   Linux-3.5.0
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    3462040 Bytes = 3.3 MiB
   Load Address: 80008000
   Entry Point:  80008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
But apparently it's Ubuntu
dmesg | grep "Linux version"
[    0.000000] Linux version 3.5.0 (ubuntu@ip-10-252-89-38) 
1)So what's going on? I am happy with Ubuntu but why would someone label Ubuntu as Angstrom and put it up for download?

2) Everytime i need to create following directory
mkdir -p /var/cache/apt/archives/partial

The next boot it's gone.

3)I can't seem to install anything using apt-get.

root@overo:~# apt-get install build-essential
Reading package lists... Done
Building dependency tree... Done
E: Couldn't find package build-essential