I could not be happier with the years of good service that CSSU has given me on my N900, I am still waiting for a phone and OS as good. The one issue that has plagued me though is the automatic rotation that CSSU introduced to Maemo5. There is the status area applet which 95% of the time prevents autorotation, but once a rotation slips past the applet(often taking as much as a second or worse jamming the UI with rotation animation when answering an important phone call!) that locked in wrong position 5% is enough to finally force my non-tech wife away form her otherwise great N900. I would really not like to have to reflash her phone back to non-CSSU over a silly rotation feature/bug.
Is there a way to spoof the accelerometer reading or comment out something in a conf file to get me back to the old reliable pre-CSSU default setting?
there is this for the N810
http://talk.maemo.org/showthread.php?t=77702
but I don't want to mess with my everyday N900 unless it is confirmed to work on Maemo5 too.
I loved the quick, easy, reliable, and fast pre-CSSU non-rotation, I am hoping we can find a way to bring it back through disabling it rather than just hoping for the unreliable applet.

did you try setting the corresponding gconf keys?

http://wiki.maemo.org/Community_SSU/Features

You can disable the rotation when getting a call.
Open the phone application click on the top menu and the last entry should be something like screen rotation don't know exactly because my phone is set to german.
There you can change the behavior of the calling application.

OK thanks,
fixes the normal rotation getting stuck issue, I had assumed that all of these gconf options were already in the CSSU Features app.

The second and still quite pressing issue, even if it doesn't cause a UI jam later, is that I believe CSSU introduced in addition to phone UI rotation an animation of the whole desktop and any active apps rather than the old phone app popping up instantly and I believe independently in portrait without any 0.5-? second hang for the animation.

Even the best case ~0.5 sec is embarrassing in a meeting when I have to wait for animation before I can silence my phone, qslideanswer helps a bit with getting a faster answer or reject screen as does using a bluetooth headset which obviously bypasses the UI though does not give the option of rejecting a call.

This everything spun with animation to portrait slowdown has caused me too many missed calls when opengl is slow to become active or the CPU or swap/memory is over-loaded for no real benefit except UI bling. I would dearly like to eliminate all rotationa animation and just, when required pop between portrait and landscape where required, which IMHO is probably only in the phone app.

There is an Orientation Lock app that works perfectly ... solved the problem on my 5 year old n900.

Frasier, biketool is right. Orientation lock works well except for the applications that force the portrait orientation no matter what. The only such application I know of is Phone, and as Halftux has pointed out, that one has an option to not do it.

Frasier, yes, I have used the app called Orientation Lock to manage the rotation problem since CSSU was released, but it doesn't kill off the turning animation related to the phone app and in about 5% or instances leaves the phone in the wrong orientation.

Halftux,
with gconftool-2 -s /apps/osso/hildon-desktop/ui_can_rotate -t bool false
in place I had to ssh in and switch it to 'true' as the Phone UI force changed my desktop orientation to portrait and it was locked that way, going to leave turning true and go back to using Orientation Lock for now.

I am trying Pichlo's suggestion and after looking again realized the phone UI if placed in locked horizontal/landscape might completely solve the problem.

I think that should happen also on a non-CSSU system, am I wrong?

yes, biketool ... i forgot to add that I locked my phone in portrait as well. but without the Orientation Lock, I couldn't control the phone app and lost many calls.

I believe, the phone application is closed and has it's own settings for rotation. This would be the same with CSSU or without.

Some applications are so old they control rotation in a "non-CSSU friendly" way, without patching those applications individually there's not much that can be done.

Also note I believe there is still a small bug in CSSU-Stable which can cause the device to not rotate correctly in certain circumstances. IIRC it's something to do with switching from Qt apps to desktop. This has been fixed in Testing a while back.

It sounds like the device is under too much load when your calls come in. Experiences of slow devices will happen with some widgetz and appletz. A fresh device is certainly snappy and evidence this is certain or a combination of extras packages that are the cause.

top and powertop/zzztop may help diagnose a CPU rogue.