Thousands of guests at the same time???

[Bill from Cleve]

I have a very strange problem and I was hoping one of you could give me some pointers to help me figure out what is going on.

For the last 3 weeks I have been getting huge amounts of guests that come at the exact same time. It started out with 500, and now it's at 2300. I believe that they all are phantoms. I just don't know how or why???

Here are the facts.

1. They all come at the exact same time.
2. They all have unique IP Address's
3. They all divide up into differn't threads. Some threads get more than others.
4. They don't appear to be moving around.
5. No vbulletin utilities register them as being there except for "Users currently online". The other addons that I installed for advanced satistics never register them.
6. No webtrend type programs show any spikes in visitors. "Other software"
7. Only happens on Friday, Saturday, and Sunday.
8. I cannot duplicate this with any Hack that pads a user numbers "FAKE USER".

If you have any Ideas, I sure would like to know.
I'm using version 3.7.4 now, but it did it with 3.7.3 as well.