Just to consolidate a few things into one message (this should be part of an FAQ, really)...
BASEBAND VERSION
This is more commonly referred to as the "firmware" version (e.g. I7500XXII5), though the *actual* Android firmware version is something different altogether (e.g. Cupcake 1.5).
"XX" refers to the Western European region, so users in other areas will have different letters here. The last three characters tell you when the firmware was released:
A = 1
B = 2
C = 3
D = 4
E = 5
F = 6
G = 7
H = 8
I = 9
J = 10
K = 11
L = 12
etc..
So the sequence is year, month release number.
IH8 = 8th release in August 2009
II5 = 5th release in September 2009
JB2 = 2nd release in February 2010 (just an example!)
Not all releases are available publicly. Some releases are internal to Samsung, so don't always expect to see the version numbers increment in sequence.
THE CSC FILE
This file uses the same numbering system as the Baseband in the last three characters.
This delivers operator-specific branding, configuration and applications. The operator can be derived from the three characters in the version number:
VIA = O2 (Germany)
O2U = O2 (UK)
ITV = Vodafone (Italy)
BOG = Bouygues Telecom (France)
You can find out your current CSC version by dialling the following "number" on your phone:
*#*#44336#*#*
A "null" value for the CSC code when you dial the above number means you don't have a CSC code.
If you don't want an operator's specific customisations and configurations, don't use the CSC file in the upgrade. You can remove the CSC file (cache.img) from a one-package firmware file using an application such as JZip (
www.jzip.com). Open the .tar file, click the cache.img file and then press your delete key.
UPDATING FIRMWARE VIA NEW PC STUDIO (NPS)
This uses a combination of your Baseband number and your CSC number. If you don't have a combination that's known to Samsung, you won't get updates. If you don't have a CSC at all, you also won't get updates via NPS.
If you can't update via NPS, you can always use Odin and the various firmwares that people make available on this forum without restriction.
APPS NOT AVAILABLE IN THE MARKET
This is down to one of two things.
1. It's a new baseband release. Google need to add this to their whitelist so you can see paid and protected apps. You just need to wait a bit for that to happen and it isn't a phone issue. This seems to be the cause of 99% of the "app not available" threads in this forum. You can modify the build fingerprint in /system/build.prop if you have rooted your phone if you need a more immediate solution.
2. You're not in a country where the application is available. Google seems to determine your country using the operator details from your SIM card (using the Mobile Country Code:
Mobile Network Code - Wikipedia, the free encyclopedia). The CSC file does *not* seem to be a factor here.
Hope this helps!
Chris