Here is what happens
I downloaded and installed "Version 0.90-beta for Ubuntu/Debian 12.04-64bit" on Ubuntu 13.10 64bit
Installed bitcoind and everything else it asked for using the button in the app
It starts just fine, creates a wallet and downloads the blockchain.
Once it did that i closed the app.
When I tried to start it later, nothing happens when clicking on the icon. Literally nothing.
The offline and testnet icons start it just fine.
I reverted to factory settings from the offline version. But starting the normal Amory icon after that does the same. Nothing.
Sometimes after restart Ubuntu says there has been system error though.
The ubuntu install is fresh and with minimal stuff installed, so it should be clean and not a problem with something else.
Is it just me?
Try starting it from the command line. Just open a terminal and type "python /usr/lib/armory/ArmoryQt.py". If it fails to load, you'll see some information about why. You can post the output here.