Android 2.3.6 on Samsung GT-I9100

Since the "bricking" and subsequent recovery incident with my Samsung Galaxy SII handset I've been on the bleeding edge of Android versions, mainly because Kies is no longer able to upgrade my phone and OTA updates don't work in my region.

I've been running 2.3.5 for some weeks and it's been rather good.  Battery life isn't too bad and I can usually go two days between charges if I'm not making too many calls.  The only niggling fault that's been there for several Android releases is the following:

Issue 16862: GSM signal strength not returned in 2.3.3

Basically it's not possible to request the current GSM radio received signal strength indicator over the API properly.  It returns a frozen value that only updates when going manually to the About -> Status menu, but then gets stuck again at the new value.  This means I can't run the RF Signal Tracker app which I'd like to evaluate for performing GSM drive testing.

Android 2.3.6 is now available so I tried an upgrade in the (optimistic) hope the above fault may finally be fixed.

The upgrade itself was pretty arduous as I run Odin through an XP Virtual Machine on top of Fedora.  After solving a BSOD issue in the Samsung USB driver when connecting the phone (answer was to emulate USB3), I managed to upgrade the phone successfully.

However, the following evening I got the "low battery" alert from the phone during the early evening, which was odd because I fully charged the phone during the previous night and had barely used it during the day.

The following day I happened to spot the battery indicator half way through the day and it was down to the last 10% or so!  Checking settings Applications -> Battery Usage the graph was a steep downwards curve with Android OS up at 93%.  The blue bars at the bottom of this screen indicated the phone was hardly ever sleeping.

I tried rebooting into recovery mode and deleting the cache but this didn't seem to help much.  I then discovered that disabling the option under settings Location and Security -> Use Wireless Networks solved the problem.  The curve on the battery monitor levelled out and actually started going back up - even when not on charge!!!  The phone then stayed up fine all evening on the remaining 10% charge.

Sadly, Issue 16862 isn't fixed either.

-- Update

I've also discovered another problem with MMS.

The handset won't send/receive an MMS message unless the WiFi is enabled.  The MMS data transfer is still sent over GPRS using the APN marked for MMS in the mobile settings.  It just needs WiFi to be enabled before it will use the GPRS connection.

... Just discovered this was happening because I used a hostname for the MMS Proxy instead of its IP address.  This seems ok on some Android handsets but doesn't work on the I9100 unless you have a working WiFi connection to perform the DNS resolution.