Also filed on the ComputerCraft side (cc-tweaked/cc-restitched#90) with a little more technical information.

Reproduction steps

• Create a new world with CC:R and IP installed.
• In the spawn chunks, place a computer and several monitors adjacent to it.
• Display something on the monitor. The easiest way to do this is monitor left paint a (assuming you've placed the monitors on the left of the computer).
• Observe the monitors display something.
• Teleport/fly away, so the chunks are unloaded on the client side. Teleport/fly back.
• The monitor will now be blank but the paint program should still be running.
• Right clicking the monitor will cause the monitor to update and the correct content to be displayed.

Other notes

I don't know if there's anything we can do on the CC side to help fix this? I wasn't sure if there was a stable/official way to hook into your chunk watching code.