[Miscellaneous Android Development] nicknc:
For those that might experience issues, I think I hit about every single one mentioned here. So here's how I got around them.

I managed to successfully install 0091 from CM without installing any prior versions of ICS. I screwed it up initially be confusing "internal SD" and "external SD" in CWM (I had an old "update.zip" on the internal SD from way back when I first installed Cyanogenmod). This caused me to apply the wrong zip (erroneously using this old update.zip), which then tricked me into thinking the zip didn't work.

I then made it worse by trying to restore the backup I'd created via CWM before installing Cyanogenmod.

This restored backup gave me the following problems:

1. Would boot to the default Lenovo 2.2 homescreen

2. Would reboot suddenly after about 10 seconds

3. Would cycle this way over and over

Then I tried just flatout flashing ICS through CWM

1. Well, this just plan failed with the "fuse error" mentioned earlier in this thread

2. I got the same error when I attempted to install the modded 1.2 zip by dawkon13

3. This really goofed me up, as it screwed up CWM, and gave me that damn android popping out of a box thing when I tried to reboot

Well, I figured it was time to do the bootable SD trick to restore my recovery

1. I downloaded the Win32DiskImager

2. I downloaded the A1_BootSD.iso provided by xbdesign

3. I imaged that .iso with Win32DiskImager onto an SD card (note, it was necessary to toggle the "all files" view filter in the open dialog in Win32DI to see the .iso)

4. This converted my 8GB SD card into a ~80MB SD card with the required CWM files

5. I copied the custom CWM created by gmarkall linked by xbdesign to the SD card as well

6. Tried to boot off the SD card, but it failed due to low battery (gave me a flash of that stupid android box, and then showed a low battery symbol before shutting down)

7. Charged my battery to about 35%

8. Booted off the SD card (didn't hold volume down or power button)

9. Once in the bootable CWM, I flashed the custom A1 CWM zip to the Ideapad

10. Powered off

11. Put my sdcard into the reader and mounted it in my PC

12. Used Minitool Partition Wizard to recreate MBR on the sdcard so I could create a new FAT32 partition

13. Copied the stock lenovo 2.3 ROM to the sdcard and then put the sd back into the ideapad

14. Booted into CWM (the installed version this time), but it wouldn't see the SD card

Well, this stumped me for a second.

1. Then I realized that the card probably wasn't formatted correctly

2. So I used CWM to partition the SD card

3. Although I was using an 8GB SD, max partition allowed by CWM was 4096, so I let it do this.

4. Set Swap to the highest value (256 I think)

5. Powered the Ideapad down

6. Put the SD back into the SD reader and back on my PC

7. Again copied the stock Lenovo 2643 rom onto the 4GB FAT32 partition created by CWM (also noted that a 3.5GB ext partition had been created)

8. Booted into CWM and installed that 2643 rom zip

9. Wiped dalvik, cache, data, etc.

10. Rebooted, and was back into stable Lenovo 2643 rom

11. Note, it DID take a long time to boot.

12. Connected to Wifi, and checked for system update

13. Was told my Ideapad was up-to-date already

This is where it got interesting

1. I renamed the 0091 OTA update to update.zip and put it on the SD

2. Tried booting into CWM, but instead got the android box failure again

3. I got frustrated, and figured I'd let it go for the night

4. Put it on the charger

5. About 1.5 hours later, I figured I'd fire up the Ideapad again to see if I could get into CWM

6. Well, I forgot the SD card was in

7. Apparently that stock Lenovo ROM also overwrote the recovery, because instead of entering CWM, it went through the stock recovery installation (it picked up that update.zip on the SD card)

8. It finished and I powered off the ideapad

9. Tried to boot up, and instead got that flashy lenovo boot screen loop for about 10 minutes

10. Popped out the SD card and entered stock recovery

11. Performed factory reset and cache wipes

12. Rebooted

13. It took about 5 minutes, but this did the trick

14. It booted up to 0091 ICS

Root, CWM

1. After this, I flashed CWM back on by renaming the aforementioned CWM .zip file to update.zip and installing it through the stock recovery

2. Then I booted CWM and installed the A1_rooter.zip file

3. Booted back into ICS and verified root achieved

SD Card Issues

1. At this point, I get two main errors (maybe you guys can help!)

2. When going settings->storage, I get a "storage has stopped working" CTD

3. This prevents me from USB mounting the Ideapad on my PC

4. Also, I cannot see or mount external or internal SD card (although CWM can see the external SD)

5. I've tried installing the A1_ICS_SD-Card.zip file linked in this thread, but it didn't do anything.

6. Everything else seems to work other than Wifi needing to be toggled on/off occasionally after resume from standby

So that's it. I hope it helps any other folks with existing Cyanogenmod to upgrade to ICS.

Also, any help on the SD Card recognition and settings->storage CTD would be appreciated.

All I can see is some 2GB storage somewhere (I guess this is tablet internal)

---------- Post added at 10:50 AM ---------- Previous post was at 10:30 AM ----------

Well, I attempted to install the stock-mbr.zip provided in another thread by Milaq, and now I have a bootloop with the initial two lenovo screens.

I can still get into CWM, and attempted a factory data wipe-- no dice.

Interestingly, CWM can now mount emmc (couldn't before), but internal sd card shows blank (when install .zip from internal sdcard is selected)

All this is in an attempt to gain access to my internal and external SD cards

Any advice?