sorry, work was crazy for the past days, did not have a chance to check the device, will do so today.

Same here - with 2 16GB A-Data SDHC cards my battery life has been dramatically reduced - nearly dead in standby overnight. Dies completely if left on longer than that. A new battery helped some - only down by ~50% in standby overnight. I suspect that the stress on the battery killed the original one. Have started to try to remember to turn it off at the end of the day - a PITA.

Running OS2008 v. 51-3 from the internal card with fanoush's modified initrd for the custom boot menu - not a modified kernel. Should probably see what happens when booted from the flash - may be that running from the card makes a difference. Will try that and report back.

I have no metalayer-crawler in the process table. Have not disabled metalayer-crawler0 in init.d or rc?.d nor renamed anything.

Phil

Update: Tried leaving N800 booted from internal flash overnight. No difference - still down to <50% battery capacity.

Estimated battery time left
When idle: 2 days
When in use: 1 hour

I recently got an 8-gig A-Data card, and also have the battery drain issue (would normally last on standby for several days, but with the card in it drains completely in less than 24 hours). Even with the card freshly formatted, containing no data, I get the battery drain. Top shows virtually no activity, so it's not the metalayer-crawler issue.

Before I was using a Transcend 2-gig micro-SD in a SD converter card, and would get some reduced battery with that (about 3 days life in standby and light occasional usage).

I got a A-data 16gb in the external slot, no problems whatsoever with battery usage.
4 day's standby. N800 with OS2008 v. 51-2 and SDHC high speed patched kernel.
I don't have a internal card however

To me it starts to sound like there's something wrong with those cards which show battery drain. There shouldn't be any, when they're not actively transferring data. Get a warranty replacement maybe?

Also make sure that you don't have swap/virtual memory turned on. Additionally, if you're booting off the card instead of the internal flash that's like to cause the same issue. The problem is that normally when it goes into sleep the tablet shuts down power to the card slots; any time that you're actively doing something on the card (i.e. using it as memory storage, using it as a boot device, etc) the tablet CAN'T shutdown the card slot, so it has to keep it active and thus drains power much more quickly.

Just to add a quick update -- I was previously getting the power-drain within 24 hours issue with my a-data 8gb card. After upgrading to Diablo (the latest firmware), the battery meter is still showing 100% after 16 hours of idle (before it would be at least half drained by now).

make sure any applets etc that routinely probe the card (such as free space checkers) are disabled - this worked for me

Recently,I find when I copy some MP3 files to N800, The default Media Player can't update playlist automaticly,and have no these songs in Library-Music-songs,Finally,I find that's because I have renamed /usr/bin/metalayer-crawler
to metalayer-crawler.bak.
When I undo it ,the Media Player is OK.So metalayer-crawler is used for scanning
the media files in system,and it is very importmant if you using default media player.Otherwise you will make the playerlist manually.If you use other Player,such as Mediabox/Canola,then you can kill the metalayer-crawler process.