Problem solved. If you are already logged in and log in again the return does not WORK
using this form the return is always redirected to the home page but it should use the redirect tag.
{exp:member:login_form return="/courses/online/53"}
<input name="username" class="form-login" title="Username" value="" size="30" maxlength="2048" id="username" /></div>
<div id="login-box-name">Password:</div><div id="login-box-field"><input name="password" type="password" class="form-login" title="Password" value="" size="30" maxlength="2048" id="password" /></div>
<br />
<span class="login-box-options"><input type="checkbox" name="1" value="1"> Remember Me <a href="{path=login/forgot_password}" style="margin-left:30px;">Forgot password?</a></span>
<br />
<br />
<input type="image" name="submit" value="Submit" src="/images/login-btn.png" style="margin-left:90px;" />
{/exp:member:login_form}
