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 (http://firmware.timelapseplus.com )
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