Twhirl doesn't give itself write access. I just installed AIR and Twhirl. As always I use a "sudo"-like script for that. This script gives Admin-privileges to my non-Admin account for this installation. This way I installed both programs (twhirl u.0.8.2). (Btw. I don't know why I had to allow twhirl hdd-write and internet access. I sure understand the internet thing, but isn't there maybe some sandbox like feature in AIR that allows me to restrict hdd-access to writing data via some Dom-Data-like interface? I felt uncomfortable having to allow the program more rights than it needs. anyway, .. maybe that's not supported in AIR. so, back to my problem.)
I then had twhirl installed and I started it without Admin-rights just as every other program. I got a dialog to choose my username. I did. I tried to hit connect. nothing happened. I hit "delete passwort". Computer thought for a second and then nothing happened. Then I deleted the account. That worked. Then I was able to create it again. But I still couldn't connect. No reaction on hitting "connect".
Then I started twhirl.exe with Admin-rights and I got a dialog prompting me for a password. I put it in. twhirl loaded all my tweets and I could use it properly.
Then I closed twirl and started it without Admin-rights. I was still logged in. And twhirl said, it'll now load current tweets. But it didn't. And it didn't display any messages in the middle of the twhirl-window. And it said "0 total (0 replies, 0 .. 0..)"
However: Starting with Admin-rights again, didn't help either. No tweets were shown, but I got a message that there was a problem with loading the direct messages. But twhirl said it did load all tweets and all replies and that I had used 6/70 reqs. But still I had a total of 0 tweets displayed in twhirl.
So I deleted my account in twhirl and added it again. Still with admin rights. That worked and I got all my tweets in twirl again.
Then I started it again with Admin-rights and all my tweets were lost again. So the problem seems independent from whether I have write access to the directory.
Just as a note: The sudo command I use can be found here
http://www.heise.de/ct/ftp/05/23/112/ as MachMichAdmin (the site is German)