SDHC: is an SD card with (HC) high capacity. This may have been the cause or 4GB may be too large for that camera. Check your manual or check their website for the specifications. I have not used that camera brand. The older cameras do not recognize these cards. As pnut suggests, a digital meter is a very valuable tool which can be used for lots of other electrical work as well as checking camera battery voltages. The sweep meter (one with the hand) is not accurate enough for smaller voltages. When purchasing new batteries, check the voltage because there is always a possiblity of a faulty one or one reading a low voltage.
As pnut suggests marking SD cards for each camera. I swap my cards out and format each one in the computer after viewing and saving what pictures or videos I wish to keep. My cards are used at random in my cameras, making sure I do not install a larger capacity card in a camera that does not recognize it. In my 2009 model Bushnell Trophy Trail camera, it has the ability to format the card in that camera. Whatever card I install in that camera is again formatted in that camera. Good luck.