Please download and install the last version of Toad (10.6) that is available on the SupportLink.
The problem does not appear in this version.
Here are instructions for downloading version 10.6.
1. Visit www.quest.com
2. Go to Support|SupportLink Home
3. If you have a Supportlink account already, log in. If you do not have one already, click the “Register for SupportLink” button and follow the instructions to register.
4. In the Downloads box, click the ‘Downloads & Documentation’ link.
5. Type Toad in the Product Name search field and choose Toad for Oracle from the drop down list. If you want to specify the version you can do that as well.
6. Click Search.
7. Click the name of the Toad for Oracle executable you want to download. It will be ‘Toad for Oracle 10.6 Commercial Installer’.
8. Choose which directory you would like the installation media to be downloaded to.
9. Once download is complete, go to directory that has installation media.
10. Double click on icon and follow installation instructions.