Steve Sinclair, the Senior Product Manager, Palm OS Wireless Products has issued statement that addresses these people's complaints. It says, in part:
Dissatisfaction with Bluetooth performance is clearly a top customer issue and our technical team has been working to overcome Bluetooth hardware limitations to deliver improved performance on the 700p. Tops among these is improving the stability of the Bluetooth connection between the phone and the headset/carkit. We hope to have a patch specifically available for Bluetooth early in the new year assuming it passes through all its certifications and is approved by the carriers. At that time, we'll be able to publish an updated compatibility list, but to be upfront about this, the number of devices we have time to test is limited, so some users may still be disappointed that their headset or carkit isn't listed. That doesn't mean it doesn't work - it just means we didn't have the resources to test it.
http://www.brighthand.com/default.asp?newsID=12689
Palm VP Promises Treo 700p Update - 12/15/2006