Steps to recreate:
[LIST=1]
[*]File->New
[*]Quest->Misc Data->Warp Rings
[*]Select '0' in "Warp Rings" window
[*]Click 'Edit' button
[*]Set 'Count' to 3 in "Ring 0 Warps" window
[*]Select '1'
[*]Observe warp location is screen 0x00 in mini-map on the "Ring 0 Warps" window
[*]Click 'Edit' button
[*]Click the square for screen 0x0F in matrix or type 0F into the "Screen: 0x" field
[*]Click 'OK' button
[*]Observe warp location is still screen 0x00 in mini-map on the "Ring 0 Warps" window, even though "Scr: 0x0F" is below it
[/LIST]
The mini-map on the "Ring 0 Warp 1" is also affected.