The Google Chrome web browser was recently updated, and the new update is causing problems with WordPress sidebars.
This is not an OptimizePress related issue - it is caused by changes to the Google Chrome web browser
There is a small lightweight plugin available which you can install on your site to temporarily fix this issue. You can download this from the link below:
Access this page and click the "Download Zip" link on the right, then go to Plugins > add New and upload the plugin and activate