Thanks for providing details about your Wordpress setup. It was very helpful.
It looks like WassUp is attempting to use the wrong table prefix for your wordpress database and can't create the tables required. I will attempt to duplicate your unusual table prefix on my test system to see if I can find and fix the bug.
The "cannot redeclare" errors are a separate issue caused by multiple attempts to install Wassup. Your uninstall/deactivation likely also failed due to the table prefix error and Wassup option settings have remained intact in your Wordpress options table. Those options need to be purged manually because any re-install of WassUp will reuse those setting, including the wrong table prefix.
To completely uninstall Wassup, first deactivate Wassup (yes, it activated despite the activation error message from Wordpress). Then, after deactivation finishes, click on "plugins" again (or reload the page) and double-check that Wassup is really deactivated. Then, delete the "wassup" folder completely from your "plugins" directory. Next, go to your phpMyAdmin manager (available from most ISP's), select your wordpress database and select wordpress "options" table (normally called "wp_options") in the left frame. Select "Browse" in the right frame and look for the row labeled "wassup_settings" under the "options_name" column and delete it (click the "X" at the beginning of the row). Be extra careful not to delete anything else as that can be disasterous.
You may have to wait for the next bug fix revision of WassUp before you can use Wassup with your configuration. Or, you can go ahead and edit Wassup plugin file to insert the correct table prefix that wassup needs to run in your setup. To do this, install a clean copy of Wassup, but DON'T activate it, then go to "Plugins"->"Editor", select wassup file "wassup.php", and edit line #63 in the "wassup_install()" function and change the "$table_name" variable declaration to:
$table_name = "marketme_wrdp1". "wassup";
Then activate Wassup. Good luck!.
FYI. For security reasons, you should not publish your Wordpress absolute path in these forums, even those in error messages. Next time, remove the beginning part of the path and only show the section after and including "/wp-content/". Michele, if you read this, please truncate the full path in this thread. Thanks.
NOTE to others reading these instructions: Don't attempt these changes! It is specific to this one case only. If you want to uninstall WassUp, go to WassUp->Options, select the "Uninstall" tab, Save, and then deactivate Wassup. That is the correct way to completely uninstall Wassup.