the way to do it is to create a transaction report for the dates you are interested in and set filter status to Unreconciled (see below).
You can adjust report in very handy ways, for example sorting according to dates (see sorting tab - same picture), rather than account names - if you are looking at expense accounts for example. I would typically want to display:
Date | Description | Memo | Account Name | Other Account Name and
Enable links - so if you find a transaction you want to look onto you just double click that link and it takes you straight into the account register. It is handy to open the report in
New Window with Page on Windows menu. Then you switch between two windows - one is the report, the other is the actual account (i.e. main window). It works well also for finding duplicate transactions - they usually are within days of each other. Just set your time period of interest and choose to
sort by amount - then run your eyes over the list - you will spot duplicates very quickly.
General Tab give the report a name. Save this by clicking OK. Then - before you close your report - use
Reports - Save Report Configuration - you will have to give the name to the report in that
Saved Report Configurations list again. So next time you can open the report quickly and just adjust the parameters you want to change (e.g. sorting). When you have made some changes, for example removed the duplicate transaction you found - click refresh button above the report.
If I want to print the reports I find that adjusting report stylesheets (under
Edit menu) is very useful - I typically decrease font sizes by 2 to 3 points to make lines fit neatly on A4 layout.