Confused, request your help!

I'm using a hack that tells the user how many days they've been registered. Then, with this information I give each member 10 posts per day they've been registered for.

Everything works fine, EXCEPT for the $postgroup which I use in the postbit template.

$regdays is OK in the postbit.
$bonusxp is OK in the postbit.
$totalxp is OK in the postbit.

$postgroup is coming out incorrectly. Anyone know why?

Here's the code used in functions.php

PHP Code:

$regdays = round((time() - $post[joindate]) / 86400); // Days Joined
  if ($regdays < 1) { // Must be registered Today
    $regdays = "1";
    $daytext = "Day";
  }
  if ($regdays == 1) {
    $daytext = "Day";
  } else {
    $daytext = "Days";
  }
  
  // Add bonus posts to users.
  
  $bonusxp=$regdays;
  
  $bonusxp=$bonusxp*10;
  
  $totalxp=$bonusxp+$post[posts];
  
  // Change postbit based on $totalxp
  
  if ($totalxp >= 1) { $postgroup = "Grunt<br>Level: 1"; }
      else if($totalxp >= 100) { $postgroup = "Wanderer<br>Level: 2<P>"; }
      else if($totalxp >= 300) { $postgroup = "Explorer<br>Level: 3<P>"; }
      else if($totalxp >= 600) { $postgroup = "Survivor<br>Level: 4<P>"; }
   
// END 

The $postgroup within the postbit template always "Grun Level: 1" even though $totalxp in the postbit template is well over that.

What have I done wrong?