I have this problem (CS3 on XP Pro): I place an image in InDesign.
Now I want to resize it proportionally.  So I hold control to resize
both content and frame together, and shift to maintain proportions.
Ctrl+shift size.  Most of the time it works, but sometimes I get the
hourglass and Ind hangs and doesn't stop hanging.  But if I focus to
another application window (it HAS to cover up the Ind window on the
same monitor) then it brings Ind back to its senses and the image is
resized.  This happens with both large AND small images where I might
resize them 2% or 50% - it doesn't matter.  The problem persists even
if I close out other applications that could affect mouse movement.
The closest I can come to pointing out the problem is perhaps,
Rorhiko's Layerlifter plugin.

Has anyone else experienced this problem?