1. Select block to place into drawing
2. Change x-scale to 1/3, observe grayed out y-scale shows (.333)
3. Click chain to unlink x & y scales
4. Change y-scale to 1/2
5. Click chain again to relink x & y scales and y-scale box grays out but 1/2 remains
6. Block is placed using x = 1/3 and y = 1/2 even though the chain shows x & y linked and 1/2 grayed out

See:
http://www.qcad.org/rsforum/viewtopic.php?f=33&t=4048