Screen size difference shouldn't be an issue.
A few more things:
- Check that your computer resolution for the second monitor is set correctly (Check in display settings) ie. 1366x768 or 1920x1080 depending on its native resolution.
- Switch the port you are plugging the monitor into (Change the 19" to the port that the 22" one is currently. Have a look to see if the 19" one then works and the 22" one displays a black screen. This can narrow it down a bit.
- Update your graphics card
driver.
I'm certainly interested to figure out what this problem is being caused by :/