Find -> List causes PSPad to lock up

This didn't happen to me until recently, and now it happens consistently.

Windows 7, PSPad 4.5.7 2450

Replicate:
Open PSPad to any document
Ctrl-F to open the Find dialog
Type some letters into the search box
Click 'List'

Whammo, the editor pane goes white, line numbers disappear from the margin, and I can't type anything in the editor or do anything useful.

I wonder if it has anything to do with SCCM software management added not long ago by our IT dept.

Search/Replace was speeded up in 4.5.8 builds. Download the newest one from PSPad developer forum