Note: In Directory Opus 10 the arrow direction has been changed to match Explorer and can not be adjusted. The information below pertains to Opus 9 and earlier.
Summary: Directory Opus displays the column header sort direction indicators differently to Windows Explorer. This can be changed if you don't like it.
Windows Explorer displays the sort arrows to indicate the shape of the sort. For example, if you are sorting by size in reverse, the larger sizes are at the top of the Lister. In this instance Windows Explorer displays an arrow pointing downwards.
Directory Opus displays the sort arrows in the reverse order, to indicate the direction of the sort. In the below example, the arrow points upwards to indicate that the sort goes from the bottom to the top of the Lister.
Directory Opus displayed sort arrows in column headers back in 1994, before Explorer started using them (or even existed), and GPSoftware believe that the method Directory Opus uses is more logical and is historically more common; however, if you wish to change the behaviour of Directory Opus to mimic that of Explorer then you can do so:
Directory Opus 9:
Go to Preferences - Miscellaneous - Advanced and turn on reverse_sort_arrows.
Directory Opus 8:
Use RegEdit to set the following registry value:
(String) ReverseSortArrows = "1"
Please note that you will need to quit Directory Opus and restart it for this change to take effect.