The order of layers in the Advanced Drawing Options (ADO) dialog box may unexpectedly change. If you apply these changes to the map your symbology will change to reflect these settings.
This is a known issue with ArcGIS versions 8.1 and 8.1 Service Pack 1. The ADO order may change upon reopening the ADO dialog box if Merge is set to Yes for one or more of the layers.
Solution or Workaround
First adjust the order of your symbols in the ADO dialog. Only after this is finalized, adjust the merge settings for all your symbols and apply.
- Finalize the symbology for all of the layers in your map.
- Open the ADO dialog and reorder your symbols as necessary.
- Once your symbols are in your final order make sure Merge is set to No for all of your symbols.
- Click Ok to close the ADO dialog.
- Reopen the ADO dialog and turn on Merge for the applicable symbols and click Apply to see the changes to your map.
- Close the ADO dialog. At this point avoid reopening the ADO dialog to change any settings.