The small black tab that appears on the side of the screen is called "DockNote". The DockNote tab can appear even when the SOHO Notes application isn't running because SOHO Notes has a helper application called "SOHONotesService" that runs in the background. If this helper application isn't running, then the DockNote tab won't appear. Follow the below steps to make sure this helper application is running and to make sure that you've enabled the DockNote tab so it appears:

1) Launch SOHO Notes

2) Choose SOHO Notes > Preferences

3) Select the "Service" preference pane

4) Select the "General" tab

5) Select the "Enabled" button. This will launch the "SOHONotesService" application.

6) Select the "Enable at system startup" button. This will add "SOHONotesService" to the list of applications automatically launched when you log in to your Mac OS X account.

7) Select the "DockNote" tab

8) Select the "Enable DockNote" button if it's not already selected. This will ensure that the DockNote tab appears on the side of the screen.

You can verify that the "SOHONotesService" helper application automatically runs when you first log into your Mac OS X account by following the below steps:

1) Choose System Preferences from the Apple icon menu in the upper-right hand corner of the menu bar

2) Select the "Accounts" preference pane

3) Select your account in the "My Account" column

4) Select the "Login Items" tab

5) You should see an application called "SOHONotesService" listed. If you don't see it listed, then close the System Preferences window and repeat the above steps. If you see more than one "SOHONotesService" listed, then this means you have more than one copy of SOHO Notes installed on your computer and you'll have problems. The solution in this case is to: a) remove all of the listed "SOHONotesService" items; b) close the System Preference window; c) find and delete old copies of SOHO Notes; and d) repeat the top set of above steps.