This often means that the Timelapse+ is unable to switch the camera mode.  While this issue is further researched, here's a way to resolved it:

1. Make sure you're using firmware version 20130502 or newer ( )

2. On the Timelapse+, change Settings->Camera->Mode Switch to "Disabled"

3. Make sure the camera is set to the appropriate mode:

For time-lapse: Manual

Bulb photo, bulb ramp: Bulb

HDR: Bulb or Manual