JUST USED MY CANON 950IS FOR THE FIRST TIME USING A SANDISK ULTRA II SDHC 4GB CARD. DOWNLOADED FIRST PICTURES ONTO LAPTOP USING THE MICROMATE WHICH CAME WITH MEMORY CARD. WHEN I'VE PUT THE CARD BACK IN THE CAMERA, A MESSAGE COMES UP ON SOME OF THE IMAGES 'INCOMPATIBLE JPEG'! THE IMAGES ARE STILL THERE ON THE CARD BUT THE CAMERA DOES NOT SEEM TO WANT TO READ AOME OF THEM. IS THIS A CARD OR CAMERA PROBLE ??

2 things the memory card and the recovery of your files.
Your camera was produced in 2005 and in those days only MMC and SD cards could be used. A few years later the SDHC came and 2011 SDXC came. devices are downward compatible. So newer cameras can use also SD cards. But older cameras can't use newer memory cards. Even a SDHC can't be used in your camera. And although I managed to buy a 4GB SD card a few years ago, now they only produce SDHC and SDXC cards. Yes be aware a 1 GB or 2 GB card now ar most of the time SDHC.
Check your card, when it says SDHC, don't try to us it, it won't work.

Then the photos from your parents. It looks we never have taken enough pictures.
When you have old memory cards, please don't use them till you checked if there are still "deleted" pictures on them.
Deleted is most of the time just clearing the pointers to the files. The files in most cases stay on the card.
Try to download some software from this site:
Memory Card Data Recovery
Then run the software, when you have a memory card in a memory card reader and see if it can find "deleted" pictures. Be aware when you use a card with "deleted" pictures, the space that came free, will be used to put new pictures there. SO don't use the cards till you did recover everything to the computer.

There are more free recover program's. I have one form Sandisk, I got it for free with a sands memory card. Login on that site to and see if they still have free program's for Sandisk users.

Success

No, it's a hardware issue. Your 8GB card is an SDHC card (the HC stands for High Capacity), but the card reader in your machine is clearly only compatible with the older type SD cards. SDHC devices will accept SD cards, but devices designed solely for SD cards cannot read or format SDHC cards.

There is no firmware update for this, your only fix is to buy an external reader compatible with SDHC cards for connection via a USB socket. Most new readers are fully SDHC compliant, but check the specs for shelling out your hard-earned...

It will take a 2 GB card, I am using one now.
I can't tell you about a 4GB card, but that's a LOT of storage, so you probably don't really need a 4GB card anyhow???

Although my SanDisk compactFlash cards 128 MB 256MB 4GB and 8GB cards are far from being full, when I open up my Canon Powershot A40, the follwing msg appears: CF card full. However, the original Canon Compactflash card FC 8M provided with my camera will still accept new photos. The problem is recent. Can someone help me.

That is odd. Try the recovery software that comes with the sandisk cards and see if you are able to get them after that.
Do you format your cards each time in the camera before shooting?

It will not work with any "sdhc"

Inspect the camera itself under good light with a keen eye. You may find a pin is bent, broken or missing in the flash card compartment. This would require the aid of a camera technician to fix. If this is not the case though, then perhaps the card has become corrupt or faulty. I would suggest purchasing a leading brand card reader(eg lexar or sandisk) as they often come with image recovery software to help in these situations. Good Luck!

Took it to Jessops by the process of elimination "Integral reader faulty."
What a waste of many hours !

I assume you mean Sandisk Ultra..and the answer is Yes it will work fine.

A good choice card also..

Just beware that some computers will need the SDHC reader.
For example my SDHC cards can be read in XP without the reader but my Vista machines need the reader.

Good luck and happy shooting :-)

According to this site

http://www.sandisk.com/Assets/File/pdf/SDHC%20Compatibility_2007-02-15.pdf

your camera does not support the SDHC cards.