Ubuntu 12.04 & QGIS 1.9.90 installation

http://hub.qgis.org/projects/quantum-gis/wiki/Download#26-Ubuntu

The good news is after having installed Precise Pangolin, I got my Ubuntu QGIS working again and not Ver 1.7.4 but Ver. 1.9.90! Is that good or bad? I do not know as it's too early to tell but generally speaking, the latest version ought to be the best because bug fixes are incorporated there just like as in cars of the latest model. However, under Ubuntu 12.04, the Synaptic Package Manager (Read the comments below, I found out later it was my mistake) does not exist so 2 pages to go to update the Ubuntu QGIS are :

•  http://hub.qgis.org/projects/quantum-gis/wiki/Download#Ubuntu and
• /file system/ext/apt/sources.list in the Ubuntu operating system

It appears now (maybe, forever) there is no QGIS version for the Precise Pangolin under the Release section but it appears under the Master section so like it or not if you want it you have to go there. Just as explained in the query below, before I installed the Masters version I did try to follow the scripts under Ubuntu : with updated dependencies but that did not get 1.7.4 running and it was only after the Masters version was installed can I use QGIS again. By the way, personally I find the icons in Ver. 1.9.90 very pleasing to see. If only they could wiggle as I pass the cursor over them that would make QGIS a fun tool to use.

STEPS
1. To play safe, uninstall QGIS 1.7.4 under the Ubuntu Software Centre;
2. Under the Master section of the QGIS Download (home)page, copy "deb http://qgis.org/debian-nightly precise main" and open file system/ext/apt/sources.list/Open with Software Sources then paste script into the input box of Software Sources/Other Software/Add (Of course, you have to click "Add");
3. The second script "deb-src http://qgis.org/debian-nightly precise main" got automatically entered so don't bother, just close Software Sources.
4. Next, under the Master section of the QGIS Download (home)page, copy the first line of the repository public key "gpg --keyserver keyserver.ubuntu.com --recv 1F9ADD375CA44993" then, under the Dash Home icon in the vertical menu bar, type "terminal' and click the Terminal icon to activate it then paste the script followed by Enter (key).
5. Repeat No. 4 but copy the second repository public key script "gpg --export --armor 1F9ADD375CA44993 | sudo apt-key add -"
6. Go to the Update Manager and update for new patch files.
7. Go to the Ubuntu Software Centre and in the search box, type "qgis". You will be surprised there is no QGIS Ver 1.7.4 but you are invited to install Ver 1.9.90 ( That got me by surprise);
8. Under Dash home icon in the vertical menu bar, type "qgis" then pull the qgis icon to the vertical menu bar;
9. Click the QGIS icon and QGIS activates without any hiccup.
10. There are of course new plugins you may like to download later under Fetch Python Plugin
11. Finish.

Now before you start,  may I suggest you a few alternatives:

• If QGIS still failed to install following the above, read the latest way to I maneged to install QGIS here.
• An alternative step is via terminal mode provided by GOwin under comments.

It is very difficult to say if a particular version of a Master will give hiccups or not, I am sure no developers wants it but since it's in R&D mode be advised or warned whichever way you may look at it. I always say give it a try but hey if it should give problems later on there is always the stable version terminal scripts to follow so don't panic. But don't stop reading. My QGIS Lisboa version as installed here. Seriously, this is a must read! I used to use the Synaptic Package Manager because it had a feature where broken links could be repaired but looks now I have to use Ubuntu Software Centre for installation of QGIS which actually is simplier

.