erratic column selection propagation in linked views or alignments containing the same sequences

Originally noticed with the following sequence of steps, but erratic propagation of column selection also happens when working in a split dna/protein view where the column selections are not mapped across to the corrresponding translation frame for some operations (e.g. select by annotation). See comments for latest problems.

Original steps to reproduce:
Opening an alignment, aligning it, and then selecting some columns followed by pressing CTRL+SHIFT+H to hide everything but those columns causes columns in the original alignment to be selected.

Looks like selection sharing is happening between alignments when the 'Hide all but selected' function is enabled.