Dev-C++ version: 5.4.2 RC5
Steps needed to reproduce the problem:
Compile anything that gets one or more errors or warnings from the compiler. Double-click on an error or warning in the opened "Compiler"-output window. Use arrow keys to move the cursor around, and observe that both the Compiler-window-lines and all toolbars (Main, Edit, Search, etc) repaint ('flicker') each time the cursor moves.
This doesn't happen before I select one of the errors/warnings and then 'enter' it (double-click or press Enter) to send the text-cursor there.
It also goes-away once I close the Compiler window -- and then comes back when I reopen it.