The K-x has had a couple firmware updates to allow better battery reading as well as adding support for 32gb and 64gb SD cards. I’ve updated to latest firmware and so far so good. Battery meter seems to be more accurate and I have yet to test a 32/64gb card on my K-x and don’t plan on it till the retail price is hovering just over $20. Below is a list of the updates and a link to download.

Changes to V1.02

• Compatible with SDXC memory card.

Changes to V1.01

• Added three kinds of particular effect shooting function (Pre-set 1,2 and 3) on [Cross Processing].
• Added assignment of Cross Processing function to the green button.
• Improved accuracy of Battery Level Indicator under specific conditions and improved stability for general performance.

How to update your K-x firmware:

===========================================
  PENTAX K-x       Firmware  Updating to Version 1.02
===========================================
* Firmware is the software that runs inside digital cameras.

  Updatable models
    K-x digital SLR cameras running Firmware Ver. 1.00/1.01.

  How to check version
      Turn the power on while pressing the MENU button.
      The Firmware version is displayed for about 5 seconds at the center
      of the LCD monitor.
      Perform the above operation without inserting the SD/SDHC card
      containing Firmware in the camera.

* * * * * * * * * * * * * * * * [Caution] * * * * * * * * * * * * * * * * *

  Use AC adaptor (K-AC84) is recommended
  If you are using AA batteries, be sure to use fully charged AA Ni-MH
  rechargeable batteries, full capacity of AA lithium batteries or full
  capacity of AA alkaline batteries and confirm that the battery level 
  indicator is displayed gGreenh (Batteries are full) before updating.

  If the camera turns off during updating due to lack of battery power, the
  camera will become inoperable. If this happens, a charge will be made for
  repairs even if within the warranty period.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

  Updating Procedure

  1. Provide a formatted SD/SDHC memory card for the update software (with at
     least 32MB of available memory space).
     The downloaded file is self-extracting.
     The following files are extracted.

            readme.txt   :  this document
            fwdc206b.bin :  Firmware

     Copy the above Firmware file [fwdc206b.bin] to the root directory in
     the SD/SDHC card.
     If your computer does not have a card slot, you can copy the firmware
     update file by inserting the SD/SDHC card into your camera and then
     connecting the camera directly to your computer.

  2. Insert the AA batteries into the camera and confirm the battery level 
     indicator is displayed gGreenh (Batteries are full)then turn the
     camera off.
      If gGreenhis not displayed, turn the camera ON and off again to
     activate the battery performance.

  3. Insert the update SD/SDHC card (prepared in step 1) into the camera
     and close card cover.

  4. Turn the camera power on while pressing the MENU button.

  5. “NOW LOADING” appears in the LCD monitor, and will change to the
     “PROGRAM UPDATE”. At the bottom of the LCD monitor,

            CURRENT VERSION 1.00/1.01 
            UPDATE  VERSION 1.02

     will be displayed.

  6. Press the four-way controller to select “YES” and press the “OK” button.

  7. “UPDATING” appears on the LCD monitor and updating starts.
     Please do not under any circumstances switch off the power before the
     update is completed.
     It will take approximately 90~150 seconds to complete update.

  8. When update is completed, the “COMPLETE” will be displayed at the left
     bottom of the LCD monitor, then turn the camera off.

  9. Remove the update SD/SDHC card from the camera.

 10. To check the Firmware version in your camera, turn the camera on while
     pressing the MENU button.
     Check that the version displayed in the LCD monitor is “Ver.1.02”
     The camera automatically starts up after about 5 seconds.

  (Caution)
    When updating is finished, the update SD/SDHC card still contains the
    Firmware file.
    If you want to use this card to take pictures, delete the Firmware file
    first.


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DOWNLOAD: Pentax K-x Firmware v1.02

FAST DL: Pentax K-x Firmware v1.02