@RichGK: Which browser and which version are you using? You might test another browser as suggested by jprateragg. Also be sure to update your Lansweeper installation to the latest version available on our
website. The report editor is a default SQL report editor. Certainly it is a bit uncomfortable if the web console performance is slow, but we can't reproduce the issues you are describing.
For all who regularly create reports, we recommend learning a bit of SQL. This allows you to easily create more complex queries and if necessary directly modify the SQL code instead of working through the GUI of the report editor and always waiting several seconds after changing anything. As long as you keep your cursor in the SQL code area, no refresh will occur on the GUI.