Bought samsung s760 and got a SDHC card put it in the camera and it says card locked,dont understand as bought the card brand new,what could it be?

When the card worked before, check if you did not switch the lock switch down. And check all contacts on the card and in the camera. They should be clean and shiny.
When you recently bought a new card you could have bough a SDHC card and these won't work in your S800.
The S800 only accepts MMC and SD cards, The SDHC and SDXC cards won't work.
A few years ago you still could buy 4 Gbyte SD cards. Now even most 1 Gbyte and 2 Gbyte cards are already SDHC. SDHC was introduced at least 7 or 8 years ago, so all new devices accept SDHC. The SDXC was introduced at least 4 years ago, so in a couple of years, you perhaps only can buy these cards?

Look at your memory card. SD cards have a slide switch along one edge. The position farthest from the metal contacts locks the card, protecting it from writes. The position nearest the contacts unlocks the card.

SD cards only go up to 2GB. According to the camera manual, you may use SDHC cards, with operation guaranteed with cards up to 4GB.

Look at your memory card. SD and SDHC cards have a slide switch along one edge. The position farthest from the contacts locks the card, protecting it from writes. The position nearest the contacts unlocks the card.

If your new card is actually an SDHC card, your camera can't use it....only SD up to 2GB.

SD and SDHC cards have a slide switch along one edge. The position farthest from the contacts locks the card, protecting it from writes. The position nearest the contacts unlocks the card. If the switch is already in the proper position, slide it fully the other way and then back again.

look at your SD card in left side there is little switch put that switch up and you good to go

emm... I have got an 2 gb SD memorycard for mine to and it wont work. Read on several places that the camera can only handle 1 gb memory card... Dont know if that's true thou.

Do the 4GB Cards say SDHC on them? They should. SDHC is simply "Secure Digital High Capacity". They're high capacity SD cards that hold more than regular cards. In this case, 4GB. The problem with these is that they need to be supported by the device. I've never put an SDHC card into a device that doesn't support them, but it looks like that's what your situation is. The highest memory capacity a non-SDHC compliant device is capable of 2GB. I recommend that you return the 4GB cards and buy 2GB cards instead.

I have been rummaging around trying to find two solutions: 1) to get my Toshiba Satellite card reader to read SDHC cards and 2) to get my desktop USB ports to read SDHC cards. While MS offers a hotfix for XP, it does not always work because of the different Chip Sets in computers. I have also read where posters say that the SDHC card works in the compter NOW, but NOW will not work in the camera... and the SDHC card NOW works in the camera but will NOT work in the computer.... I found a tekkie article that may help clear the air... SDHC cards are formatted in Fat32x (NOTICE the "x") and SD cards are formatted in Fat32 (no 'x') and these compatibility problems arise when the user unwittingly or unknowingly RE-formats the SDHC card, either when it is put in the computer and won't read or when it is put in the camera and won't read... but just don't bother to mention that THAT is what they did upon inserting the card and only proceeded to complain about an apparent incompatibility. The camera or computer might even mislead you asking if you want to format the card..... but all is not lost. The Panasonic site gives a program AND a pdf instruction book on How To ReFormat an SD or SDHC card specifying the proper Fat32x or Fat32 format. Hope this helps.