[BirdOPrey5]

Log into the Admin CP.

On the side menu expand "Products & Plugins"

Click on "Plugin Manager"

At the very bottom there is a link to "Add New Plugin"

On that page put in the following information-

Product: vBulletin (this should be default)
Title: Tab Fix
Hook: member_build_blocks_start (from a drop-down list)
Execution Order: 5 (default value)

To make Visitor Messaging the default past this into the PHP Code box:

PHP Code:

if (!$vbulletin->GPC_exists['tab'])
{
    $vbulletin->GPC['tab'] = 'visitor_messaging';
} 


Or to make About Me as the default paste in this instead:

PHP Code:

if (!$vbulletin->GPC_exists['tab'])
{
    $vbulletin->GPC['tab'] = 'aboutme';
} 


Save the plugin and you should be done- go to a profile page to test.