I wasn't really blaming Maemo, I'm much more blaming my silly experimenting. It was a rant coming from tireness, and from the unpleasant feeling that Maemo is drowning.

However I was running at normal voltages and megahertz. I'd greatly appreciate a way to make my filesystem(s) more resilient. The Ext3 journal seems not a great help.
And, I'm using ver 46 to be able to connect to usb sticks, which is a good thing when I'm on my n900 only.

I think this is wrong. v46 seems perfectly stable to me.

It's switched off by default. There's a reason why it's switched off. There's a reason why it can't be switched on through the normal user interface. There's a reason it can only be changed through activating shoot-self-in-foot mode in X-terminal, also known as root. Perhaps it should be removed entirely in the next update so people don't try switch it on, so they don't get the wrong idea.

Just guessing: It may be caused by bad partitionning (e.g. overlapping partitions). You may try to repartition the internal flash or reflash it.

I've also got exactly the same problem when i tried to put my swap partition on a fast microsd card (but i've got no reasonable explanation for this one: there was no i/o errors recorded and the card was perfectly running otherwise)

After reloading with dd an old image of my opt partition, instability seems over, even if it's too early to be sure. It must be that, though. Next time opt seems unstable I'll do an emmc flash and start over.

Power 42 = PR 1.2
Power 46 = PR 1.3

That could be why he is using Power 46.

I've had an issue with the file system when I used proposed parameters from swappolube.
More specifically with transmission app. - would have too unmount and fix the file system

Currently I returned to original parameters and haven't had any issues since.

Nope, kernel-power has integrated the PR1.3 patches since 2.6.28-maemo41. See the changelog on the following page:
http://maemo.org/packages/package_in....6.28-maemo41/

A week has passed and my n900 has been stable and steady again, even with overclocking. It was something in the partitioning of the internal flash, for sure.
I advice those who suffer the same problems to:
1) backup the /home/user/MyDocs directory, including the hidden directories (e.g. .documents, .images, .videos
2) backup your personal stuff with the stock backup utility
3) reflash rootfs and emmc
4) reload everything from your backups.

I have been having exactly the same problems as you for the past 9 months. I would like to know before I actually reflash the eMMC, whether the problem has resurfaced again since your last post.

For a while I thought it was the following:
* power kernel (42 or 46) with standard voltages (or at the max the lv profile)
* themes
* clockspeeds (I excluded 250, then everything beyond 800)
* swappolube

None of these helped. It used to crop up at random, usually at very high load but even that wasnt very consistent.

I repartitioned the eMMC manually from my PC using BackupMenu's read-write mode, but even that hasnt helped too much.

@mattbutsko:
Power kernel v46 changelog states that u-boot has been disabled and bluetooth support has been added. Thats the only diff between 42 and 46, so I guess it should be identical to using 42.