For my site, I just turned SEF off for CB.
Looking through the forums, it seems if you disable just the 2 SEF translations for Registration and Lost password functions, everything works fine.
Looking over the code, you can try changing components/com_comprofiler/comprofiler.html.php
<form action=\"<?php echo sefRelToAbs(\"index.php?option=\".$option); ?>\" id=\"adminForm\" name=\"adminForm\" method=\"post\">
Change to:
<form action=\"<?php echo index.php?option=\".$option; ?>\" id=\"adminForm\" name=\"adminForm\" method=\"post\">
and around line 1263
<form action=\"<?php echo sefRelToAbs(\"index.php?option=\".$option); ?>\" method=\"post\" id=\"adminForm\" name=\"adminForm\" onsubmit=\"return submitbutton(this)\">
Change to:
<form action=\"<?php echo \"index.php?option=\".$option; ?>\" method=\"post\" id=\"adminForm\" name=\"adminForm\" onsubmit=\"return submitbutton(this)\">
Note, these changes are UNTESTED, so backup the file first.
A better solution would be to fix the SEF file instead, but I don't have the time to check that one out.
Let me know if this works for you, as I am setting up a few more sites and would be interested if it works or not.
