Milton wrote:
...when users attempt to login, the login form does not go away and the user menu never appears. In other words, it still acts like the user is not logged in. However, when looking in the backend, the user is logged in.

I'm having the same problem on my site. On this site, all users are required to login before they can see content. If they haven't logged in, the login module is presented to them. The user enters their user id and password and clicks the "Login" button. And then the problem occurs, that is, the exact same screen appears again with only the login module on it, no content. I've been having this problem since I installed this site, here are my findings so far...
Similarities to others experiencing this problem:- After clicking "Login" the user is listed in the backend "Currently logged in users" list
- This is a Joomla 1.0.8 Sunshade installation on IIS, Windows 2000, and MySQL
- The problem has existed since the beginning of this installation
- The Joomla installation is not hosted on my PC
Other interesting findings that I've come across:Second time can log inWhen the login screen re-appears, if the user tries to enter his/her user id and password, they are then logged in correctly. This action occurs every time. That is, users must login TWICE, then they can access content.
Log in, log out, log inIf the user does log in (after the second attempt), and then they log out, and then they try log in again, on this occassion, they only have to type userid and password ONCE.
Incorrect uid or passwordIf the user enters an incorrect user id or password, a pop-up message indicates this, suggesting that the login module is doing what it's supposed to.
IE or FirefoxThe same problem occurs whether the user is coming from IE or from Firefox.
Login redirection URLThe problem is not fixed by using the Login Redirection URL as some other people have suggested. I have tried many different entries here, including full URL path, only the index.php part of the path, as well as leaving this option blank. Also, I have tried these different settings in combination with different settings in the configuration.php file. I only seem to get progressively worse results, nothing seems to fix the problem.
WWW prefixIn my case the WWW prefix issue does not apply since our installation is running inside our comany's network. The URL for our server does not include the WWW prefix. This suggests to me that this problem occurs regardless of the WWW issue.
configuration.php mosConfig_live_site settingI've tried different settings in the live_site setting. Everything from IP addresses to DNS to URL names. When I ping the machine with any of these names, it always works. More significantly when I use the backend there are no problems (unless I make the live_site setting something completely wrong). Finally, the user is able to log in after the second attempt, so something must be right.
Keep tryingIf anyone else has some light to shed on this problem, I would really appreciate it. We're due to go live with this site in mid-October and I've been struggling with this problem since installation back in May! I don't want to step on anyone's toes but this does seem to be a bigger problem than some of the members of this Joomla board want to admit. Even if it is eventually found that the problem is just a configuration problem, there needs to be some clarity on
how the problem occurs, and
how to avoid it.
I'll keep trying, hope others do too... eventually, something is bound to come up.