[Gen9, Gen10 General] 55mls:
Although I have read of others having the screen stay black/blank on wake up, I really have never had that problem with any firmware version on my Archos tablets Could be something due to the many changes in hardware they have made (all with the same G9 model name). Or, maybe some bad apps or task killer (task killers actually create far more problems than the solve anyway).

Part of that is simply due to Google having added more of their own junk into Android that seems to always want to keep running in the background (syncing for Chrome, Google+, etc.). Then, on top of that, Archos has added in some really freaky stuff for their "MediaCenter" and "file indexing" that is really messing things up!

On a device with PROPERLY WORKING ANDROID FIRMWARE you should never have to ever kill any background tasks. That is what the memory management is supposed to be taking care of by itself in Android. However, I do not think Archos has fully fixed the memory management problems yet with 4.0.26. Hopefully things will be better in whatever newer firmware they release.

People with the newer Archos tablets that have 1GB of RAM do not seem to notice the memory management flaws, but it is something that causes a lot of problems for those of us with the older "classic" models that have only 512M of RAM.

[Side Comment: And with all the extra stuff Google has been adding into things I really do not see Jelly Bean ever working correctly on any device with only 512M RAM. Even ICS barely works with less than 1GB RAM. Some companies are already making devices with 2GB RAM just to stay ahead of whatever Google may come up with in the future.]

Not sure just why you (and a few others) ever had that problem to start with, but hopefully you can now limp along somehow until Archos releases a newer firmware.

On my end, here the problems I've found with the "official" Archos 4.0.26 (including even with a test release they had e-mailed me a link to try out):

1) Problems with graphics in certain games (ShadowGun and Max Payne). I've posted a YouTube video of that http://youtu.be/qQjMhykykxw

2) Sound does not work after some point in playing the game Asphalt 7.

3) There is no up/down arrow notification WHILE a Bluetooth transfer is in progress, so you can not tell if it actually is transferring... nor can you check how far it is in the process. Only displays a notification AFTER the transfer completes (or fails).

4) Whatever this stupid "file indexing" is... it starts up for NO LOGICAL REASON especially right in the middle of installing certain apps... mostly games that may have sound or video files as part of them. Also...

5) Whatever the new stupid things added in to "MediaCenter" and "file indexing" cause everything else to slow down to a snail's pace and/or cause the device to run out of RAM... causing crashing problems, or else making the device just about totally un-usable until it finish whatever that "indexing" crap is trying to do.

6) Not sure if it is from the above, but random crashes still occur out of nowhere for no reason. So, I don't think they have the memory management totally fixed yet either.

7) Because of things crashing in the background, the battery level and any charging is still not working correctly either.

If you REALLY only have had a problem with the screen being black/blank on wake up... well, guess you really do not do as many things with your tablet as I do. There are a bunch of flaws Archos still needs to fix in the next firmware release BEFORE I will ever install it. Although I do NOT need/want "root" I'm staying with the rooted stock 4.0.7 until Archos fixes things in their official firmware.

I'm hoping for a new firmware about middle or late January, but who knows if/when it may happen.

Anyway, glad you are having better luck on your end now. Seems to depend on if you have 1GB RAM or not, and oddly the 80 G9's seem to work a bit better than the 101 G9's do for some reason (or at least with my older "classic" models anyway).