Cannot select multiple items in data browser

I seem to have triggered some setting so now the data browser will not allow me to select multiple items. If I hold the shift or command keys and click different items, the focus just shifts to the last one clicked instead of allowing me to make a selection. It happened after I randomly hit a few keys on the keyboard, but cannot seem to figure out what they were or where to look to track down the setting that changed. This behavior persists with new experiments and old ones, and both after relaunching Igor and restarting the computer.

Any suggestions?
I am seeing this also.

Additionally I cannot use the the alt key shortcut to select the active data folder

Igor 6.36 on Mac 10.10.3

I'd recommend opening the keyboard preferences and checking there the setting for Modifier keys. It sounds as if you experienced a change in setting, similar to what happens when activating a keyboard for a different language.

WaveMetrics, Inc.
I clicked a couple of things in the preference window and that did not work until I restarted.

After restart it appears to work correctly.