It can be used, but not always. Some people get lucky. Others don't.
Which is why we recommend an SD proper (no adapters) no more than 2 gig, Sandisk branded, properly formatted (full erase using the Panasonic SD card formatter, not quick format) for maximum compatibility.
Try your SDHC if you want, but don't come back saying "So and so said it would work and it doesn't, what should I do?" because I've already answered that question above.