Delay in logging Drupal user through Services
This looks unrelated to drupal itself but it's more likely to be a glitch / misconfiguration in the web server/LAMPP settings or a DNS lookup issue.

Can you please let us know more about your LAMPP stack and OS?

Also consider trying the following:


Setting the ServerName property in httpd.conf ( ServerName
  127.0.0.1:80 )   
If the above doesn't work, in your httpd.conf be sure to set the setting HostnameLookups Off
Enable slow query log in MySQL.
Have a look at this post https://serverfault.com/questions/66347/why-is-the-response-on-localhost-so-slow