That is true if you use the icon in "Dash home". I found it is best to install the v0022 from the repository first! That way you get all the avr toolchain upgrades from the Ubuntu repository too.
Then download the Linux version of 1.0 from the Arduino website. Unpack it in a local directory. In that directory you will find a arduino shell script. Run it and you get v1.0.
You can still run v0022 by selecting the icon on the "Dash home" if you want.
I'm running three versions now:
v0022
v1.0
v1.0.1 rc1
When I double-click the arduino shell script, I get a popup screen asking me what I want to do with the script. I select "Run". It takes several seconds to boot up. You don't get that prompt?