Lexar (MDA256-100 Rev A) does not recognise 'SanDisk Ultra 4GB SDHC' card. - Player works fine without card (using its own internal memory), but completely freezes / becomes unresponsive when SD card is inserted.

Are your computer's card reader and camera compatible with SDHC cards or only with SD cards? While SDHC cards will fit into SD devices, they are electronically incompatible and will not work in devices not designed for SDHC cards.

You may use any SD card up to 2GB in size (4GB if you can find any). Make sure you get an SD card and not an SDHC card, as the latter are electronically incompatible and will not work. The brand and speed won't make much difference, though a faster card may download faster to your computer if you use a compatible card reader. I'd also stick with the major brands, such as SanDisk, PNY, and Lexar.

A 4GB memory card will be an SDHC type. SD and SDHC cards fit the same slots, but many cameras won't work with the SDHC (high capacity) cards. SDHC is not backwards compatible.

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...

Hi If your card is SDHC version is possible that you card adapter doesn't support it, you have to try another one.

It will not work with any "sdhc"

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 :-)

When You Insert your SD card into the internal card reader, then the SD card is not recognised by the system and the SD card drive doesn't show there. The problem can be because of driver issue, system issue and device issue.
To fix the problem you need to go at device manager if there is a yelllow sign in SD card controller, the problem is most probably caused by a driver issue. Then you need to update the driver. You can also download the driver for your card reader.
Also, check if your SD Card is broken. You can also check it into different devices port.
If it is detected then you can backup of your data.

If the problem not resolved by any means and you require you SD Card data then I will suggest you read - https://www.stellarinfo.co.in/services/removable-media-recovery.php

I went onto the BestBuys site and found a link for compatible memory cards - The SanDisk SDHC isn't compatible with the Canon Poswershot SD750!! Only a 2GB card will work. The Lexar SD and the Kingston Technology 2GB will.