can't tag items with a tag once the tag has been hidden
Nominated for Trunk by Bill Wohler
Create a new item called "item 1" and tag it "mytag". Go to the tag list and long-press "mytag" to display options. Select "hide on homepage". This will rename the tag to "_mytag" and it won't display on the homepage.
Create another new item "item 2", and start adding a tag by typing "myt"... Astrid's auto-complete feature will not show you the option "mytag" as you type. Erase that tag and start typing "_myt"... Astrid will show you "_mytag" as an option. Erase this tag and just add the original tag name "mytag". Save the item and go to the tag list. It will show 2 separate tags "mytag" and "_mytag".
My suggestion is that we should be able to add tags by typing the original names, and we should not be able to create new tags with the same name as the hidden tag.