Nice to see fpc 3.0 with UTF-8 in RTL supported now, great work!
The new desktop configuration (controlled under Manage desktops dialog) does not remember coordinates on a secondary display with anchor docking active (not tested undocked). Once Lazarus is opened again it jumps to the primary display and shape of windows change, apparently scaled relative to the edges of the screen. It is very awkward to then move it back to the secondary display again if the Scale on resize option is off (necessary to avoid the bug where the messages window keeps growing every time Lazarus is started), as the window has expanded. If for instance code explorer is kept at the right edge, it will be out of the window with the screens specified below.
This works fine in the 1.4.3 fixes branch before the new desktop configuration was introduced; Lazarus stayed on the secondary display with everything at the last used coordinates.
This is tested under Win 7 64 bit system, 32-bit Lazarus, primary display on notebook computer is 1920x 1080, secondary display 1600x1200, extended desktop mode.
Edit: I have now reported this in bug report #0029184.