Ok if you are one of the frustrated people out there that are having problems connecting your Windows Mobile devices over Bluetooth due to the incompatibility of having Toshiba Bluetooth drivers, I have come up with a work around solution. I have a Fujitsu P1610 that I always had problems syncing over Bluetooth with my Windows Mobile devices in Vista, but never thought much of it since I sync mostly over the air with Exchange and those instances where I needed to sync my device with my P1610 I did it over USB. Also using my Windows Mobile devices as a dial up modem, shared internet connection, audio device, or PAN connection always worked. I was recently trying to use SideShow to setup for our meeting and it wouldn't work so I tried a few "work arounds" and finally got it to work.
1. In Device Manager-> Right click on each item under Bluetooth and Uninstall ALL your BT devices. I chose to delete the driver as well, since I had a backup of them under C:\Program Files\Toshiba\Bluetooth Toshiba Stack\Drivers (as well as the rest of the Toshiba Bluetooth software) and could reinstall them if I wasn't happy.) The only downside of using the MS stack is that you loose Toshiba's support of Bluetooth 2.0+EDR (Enhance Data Rate), which provides Bluetooth 2.0 EDR compliant devices speeds up to 3.0 Mbps. So if you are tethering using a 3G connection without EDR you wont' get your 3G speeds. Our buddy Arne Hess over a the unwired has some speed tests on that here.
OK make sure you delete all items of the Toshiba Bluetooth Stack from Device Manager under Bluetooth or you may run into some problems later on.
2. Turn off your BT device. I did this via my wireless switch if you don’t have it you can do it via the Toshiba Bluetooth Monitor under Options in the Program Files->Toshiba->Bluetooth Toshiba Stack.
3. Restart your PC.
4. Download from Microsoft website the IntelliPoint 6.2 (32bit/64bit) for Windows Vista Drivers and install them.This will install Microsoft's latest Bluetooth drivers. You don't need to have a Microsoft mouse. I went this route since I have a Microsoft Bluetooth keyboard and mouse and finally decided to install the software as well to take advantage of all the pre-programmed keys on the keyboard and buttons on the mouse, that didn't work with just standard Bluetooth Human Interface Devices (Bluetooth HID) drivers.
Note: If you don't want to add anymore software to your computer, some people have got this work around to work by using drivers already existing on their computer - the Cambridge Silicon Radio Ltd. Generic drivers, which manufactures most Toshiba Bluetooth products.
5. After installing the Microsoft IntelliPoint software you don't need to configure a mouse if you don't want to. :)

6. Next turn on your BT device. It should appear under Other devices and you will see your BT device as an Unknown device with an exclamation point error (because there is no driver)
7. Right click on it and choose Update Driver Software.
8. Vista will ask you how you want to search for your driver software. Choose Browse my computer for driver software.
9. Next choose: Let me pick from a list of device drivers on my computer.
10. Next choose Bluetooth Radios.
11. Next select the Generic Adapter from the drop down list on the left and the Generic Bluetooth Adapter from the drop down list on the right, well its your only choice. :) This is the generic Microsoft one.
12.Next accept the Update Driver Warning that comes up by clicking Yes.
13. Now you should receive a message that you have successfully installed your Bluetooth drivers.
14. If you look in Device Manager you should see your hardware installed.
15. To configure and add devices head to the Control panel and you will see the Bluetooth Devices icon. Click on it and add your devices.
Make sure your device can be discovered and your device should come up. Select it and click on Next.
Your Windows Mobile device will then be installed along with the appropriate drivers.
Be patient and your device will be ready to use. You will also now see a Bluetooth icon in your Taskbar.
If not, you can you can make it visible under Bluetooth Devices-> Options tab-> Show the Bluetooth icon in the notification area.
If you don't like the MS stack and feel it delivers less due to the lack of profiles from the original Toshiba stack you can remove the Microsoft ones and reinstall the Toshiba ones or install Virtual PC with an image of the other stack for the times you need it. :)
Enjoy!!
Update: Toshiba has released a Bluetooth Sideshow driver update via Windows Update.