My uniden guardian will not accept a new s.d. Card the monitor keeps saying card error,what do i do?

You need to buy a new memory card or to erase files on the current one you have on the device.

I was getting the same trouble with the "record file error" always showing up on my monitor as well, and no recordings were being written into the SD card. I tried different SD cards and the same message was appearing. I was about to pack it up and return it to the store until I did one last thing...and it worked for me! Solution: Using a paper clip, insert the end of it into the "reset" hole under the SD slot and the system will turn off, restart, and voila!...it will start recording again. I hope this helps everyone who has this similar problem out there. I guess the unit just need a good reboot and get some of the bugs out of it's system.

While viewing recorded video and G755 monitor touch "X" to delete each video.

First, make sure your camera can accept SDHC cards. If the camera says the card is locked, move the slide switch on the side of the card.

Your camera may not accept SDHC cards. Check your manual.

It's possible that your camera is not compatible with the new card.  The C-350 and D-560 will only accept cards up to 512 MB <URL:http://www.olympus.co.uk/consumer/208_1212.htm>.  You might want to check with Olympus anyway: there might be a firmware update or something.

Unfortunately, most shops only carry the bigger cards now, if they carry xD cards at all.  If you bought the card from Crucial, I would expect they would take it back if it's not compatible.

Sounds like you didn't format the cards in the camera first before using them. Try that now.

A520 will only work with SDcard up to 2GB

Check in the Manual that the camera can accept 2Gb.
If it say it can then return the card for replacement.

I know this is a silly question but are you putting the sim in correctly?