My live site is listed as 'http://www.mysite.com' in global config but if I went to 'http://mysite.com'I most often had a pop up box that would read "Please complete the username and password fields" when I went to log in and I usually was not able log in.  My problem was fixed by using a redirect to use www. everytime, see the thread here: http://forum.opensourcematters.org/index.php/topic,1474.msg13133.html#msg13133

I thought my problems were somehow related to being bridged between Mambo and SMF but it seems to be mostly Mambo problems not at all related to the bridge or SMF.  Here's a fix for erractic online guests, it has worked perfectly so far.  And for whatever reason I could not login without www. in the address which gave me an error pop up message, here's what worked for me: login error without www.

My name still appears multiple times in Currently Logged in Users which seems to be another problem that many Mambo users have encountered before but I haven't found a good solution listed in any of the forums yet.

I need to switch a site from my current hosting service and I can't help but notice the ads for Mamboserve Hosting here.  It looks almost too good to be true for what they offer at that price so I am looking for people who have experience in dealing with the company.  If they're a reliable company then I would register with them almost immediately, but I'm a little hesitant without hearing some feedback.

Again I could not login using the login form. I made a mistake in the other post, I did not refresh the page but rather had to login to Mambo admin and then logout from there in order to use the login form in the front-end.  I have also noticed that sometimes I'm not logged in but I can edit the front-page item.  That's all the quirky and frustrating things I've noticed so far.  My web knowledge pretty much only goes so far as html and beyond that I have to diligently follow instructions so I won't be of much assistance in solving this problem, but I can at least raise awareness and hopefully someone can come up with a solution.

One more thing to add; Remember Me does not work in the login form.  I'm thinking that these problems are all related, and as I said before only started after the upgrades.

No, the only thing I'm using that's not Mambo default is Coppermine, everything else besides the forum is straight "out of the box". The first thing I upgraded was the new bridge and that's when I first noticed the Who's Online to be incorrect, I think it would say 2 members online when it was just myself.  Then as I upgraded everything else over the next few days the number of guests shown went haywire.  I was using an older Login module and it seemed that when I installed the new one, things went out of control, but since I upgraded everything almost simultaneously it's hard to tell. Also, in the Currently Logged in Users in Mambo admin it quite often lists my name two or three times. 

Perhaps unrelated, one time I could not log in using the Login Form.  A pop up box would read "Please complete the username and password fields", after refreshing the page I did manage to log in.

The only thing that I could contemplate that might be out of the norm is using a Mambo template which I believe was created during Mambo 4.5, I only needed a couple of quick changes to get it going in 4.5.2 and I've changed the layout, but other than that everything would be as if it had just been installed.

The number of people shown online on my site is out of control.  I have a very low traffic site and there likely isn't anyone visiting the site other than myself right now.  But Who's Online showed well over 400 guests, when I logged into Mambo admin it showed about the same number, everytime I clicked on something in the backend it would just keep adding more and more guests, then after a short while when I'm logged in it gradually eliminates the phantom guests completely.  After some time it adds more visitors everytime I click something in Mambo admin and starts the cycle again.

I fell behind in upgrading so I just recently upgraded everything at once and that's when the problem started.  Now using SMF 1.0.5, Mambo 4.5.2.3, Mambo-SMF Forum v.1.3.1.3, Login Module v.1.3.1a,  Who's Online Addon Extensions v.1.0.