I don't know if it's worthwhile raising issues with v3 as the developers are now working on v4. You can download an Early Adopter version available on OTN I think.
If you're new to SQL Developer, it's worth knowing that a single click on an item in the navigator tends to do what you would expect a double-click to do. I think a double click can cause the same action to be started twice.
Thanks for the reply.
There is a setting under Preferences that allows you to set single or double click to open things. Unfortunately this setting does not appear to solve this problem.
Thanks for the tip - that's a minor annoyance removed for me! Hope your original problem is fixed in v4.
Thank you for your feedback. Similar issues with the persistence of grid settings has been reported recently. Clearing the settings seems to improve the situation but it does return. It is still an issue in 4.0 EA2 but I investigate further and hopefully get back to you.