I should have added that my hardware configuration is slightly different now:
Laptop: Thinkpad T60, with a 1400x1050 screen (4:3)
Home external monitor: Dell S2409W with 1920x1080 resolution (16:9)
Work external monitor: HP LP2065 with a 1600x1200 resolution (4:3)
However, the behavior is identical to what I initially reported.
I should have added that my hardware configuration is slightly different now:
Laptop: Thinkpad T60, with a 1400x1050 screen (4:3)
Home external monitor: Dell S2409W with 1920x1080 resolution (16:9)
Work external monitor: HP LP2065 with a 1600x1200 resolution (4:3)
However, the behavior is identical to what I initially reported.