Apple has updated its BlueTooth software to version 1.4.1 (for OS X 10.3) and 1.3.3 (for OS X 10.2). Both updates add increased stability and performance. From the short release notes in the Software Update Control Panel:
Bluetooth 1.4.1 for Mac OS X provides enhanced stability for Bluetooth connections. This release also improves performance with human interface devices (HID) including enhancements to wake from sleep.
BlueTooth Software 1.4.1 is available from the Software Update pane in OS X 10.3, and version 1.3.3 is available from OS X 10.2is Software Update.