Using Firebug you can see that this is controlled by
[code:1].titleCell {
width:125px;
}[/code:1]
Edit the template.css for which ever template you are using located here:
[code:1]components/com_comprofiler/plugin/templates/MY_TEMPLATE_NAME/template.css[/code:1]
Please keep in mind I am not sure everywhere this is ued, but they will all be increased, which you probably want anyway. Since this is inside a div ID called "registrationTable", you could add this to the bottom of your template to effect .titlecell on this page only:
[code:1]#registrationTable .titleCell{
width:250px;
}[/code:1]