Which transaction is this happening with? Problems with tab caching are often due to overwrite rules being wrong for a transaction. Check Chinthan Yajamaan's blog SAP Screen Personas Screen Id and Control Id overwrite rules to understand what they are. There's a link at the end of the blog to OSS note 1999747 that contains the current recommended set of overwrite rules - compare this list to the ones in your system and add any you have missing, especially if they are for the transaction you are having trouble with.
If this isn't it, you may have to open an OSS message.
Steve.