Thanks for posting on the forums.
I think you are exporting and importing whole wp_options table, you don't need to export/ import whole wp_options table for exporting / importing custom sidebars settings.
To import / export only the Custom Sidebars settings execute the following sql query in your PHPMyAdmin sql executer.
SELECT * FROM<code>wp_options</code>WHERE option_name = "cs_sidebars" or option_name = "cs_modifiable";
Then on the generated results page select all the two found rows by clicking on the "Check All" text and export it by clicking on the "Export" text as described in the following reply.
If by any chance according to the configuration of your PHPMyAdmin the exported sql file contains the wp_options table creation code as following
CREATE TABLE 'wp_options' (
then before importing just change the above code in the generated sql file as below so that when importing it won't generate "Table 'wp_options' already exists" error message
CREATE TABLE IF NOT EXISTS 'wp_options' (