losing contact when installing packages

[MacValley]

I have been running my pi for a month now and it works just as expected. However, most often (but not always) it hangs at the end of installing a new package.
I use wheezy from 2013-02-09. Whenever I want to install a new package I start with "sudo apt-get update" to make sure I am updated.
Just now I installed LibreOffice using "sudo apt-get install libreoffice". The process started as expected asking me to accept the amount of memory needed. So I did and it started to download, unpack etc. Then, after say 20 minutes or so, nothing more happened. From another computer I pinged the pi and connection was lost. Then I rebooted by powering off/on. Then I could see that LibreOffice was actually installed. When I connected using VLC I could start it from the start menu just as expected.
But surely I should not have to reboot after an installation?
LibreOffice is just an example. I also installed Synaptic (had to reboot since connection once again was lost), and with Synaptic I then installed RabbitVCN subversion client. No matter if I use apt-get or Synaptic. Once the installation is finished the connection is lost and I have to manually reboot.
This is particularly irritating since I use my pi remotely, and use ssh or VLC to connect via network cable.
I am not sure but I don't think I had this problem with the earlier wheezy (dec 2012).
Anyone else having this problem?

[FTrevorGowen]

How do you connect to the internet ie. are you using a wired or WiFi connection to a router, or by "internet connection sharing" or similar via another computer. Generally I've not had any problems with wired connections but occasionally a WiFi connection has been lost. However, in my case, it's probably my router that's the problem since it sometimes "loses" my wireless printer (even though the printer thinks it's still connected) and I have to re-boot that. Since I've only one HDMI/DVI monitor, I often work "headless" too, but using a PuTTY ssh client since that can be used within Linux or Windows (my net-book is "dual-boot") and supports "X-forwarding" and "tunnelling" etc. The only times I've had installs "hang" (whether via apt-get, aptitude or synaptic) has been when "too many" of the software to be installed "dependencies" cannot be fulfilled (ie. the needed files could not be downloaded). This has usually been as a result of not doing a "sudo apt-get update" (which you are doing) but may have also happened when a "sudo apt-get upgrade" hasn't been performed.
Trev.

[MacValley]

Trev, when I mention "losing contact" I do not mean the Internet. When using apt-get, the pi always downloads dependencies, then it starts unpacking etc which is a local action at the pi itself. When all dependences have been installed, then for some reason I can no longer connect to the pi, the network interface is simply down. But when I reboot I can see that everything WAS actually installed. It is as if something fails just when the last item has been installed, and the network dies.
So far, when I say connect remotely to the pi, I have the pi in the same house, with a wired connection to my home network. Of course I can go to the other room and plug the mains off for a second to reboot but my intention is to remotely use it over the Internet, placed some 100 km from my home, and THEN I do not want it to behave like now!
MacValley

[FTrevorGowen]

Trev, when I mention "losing contact" I do not mean the Internet. ...
MacValley

Neither did I, specifically, it's just that, for many folks their LAN is provided by their router, which may be wired only, WiFi only or, like mine, both wired and WiFi. Since you have confirmed that your LAN is wired then a "known issue" with WiFi connections can be ruled out. This suggests that we're now dealing with a software problem and/or a "corrupted" OS image/SD card. If you've run "sudo apt-get upgrade" as well as "sudo apt-get update" and the problem has persisted then, just maybe, your SD card/image is "flaky". Whilst I'm aware that changes in the Feb 2013 release may have affected HDMI connection (hotplug) detection (and have noted such here, and in the wiki), so far no one else (yet) has flagged up "network connectivity" issues. I don't think it's a direct problem with "apt-get" etc. as such either - I would have expected a "flood" of queries if that were so. However all of the "installation tools" do have to update their databases on the SD card when they've finished which is, perhaps, a "clue". Sorry I cannot be of greater help. Trev.

[MacValley]

Dear Trev,
Thanks for the clues! Since no one else (yet) has answered I am just like you beginning to think the problems are local to me.
If time given, I will connect the pi direct to keyboard/mouse/HDMI instead of installing via network/ssh. Then I will see what happens direct on the monitor.
I think my plan for remote actions will be that I plug the remote pi's power supply into a NEXA receiver. I already have a few receivers, being able to remotely turn heating on/off in our country house via Internet and Tellstick Net.
Maybe overkill, but in that way I am sure that I can remotely switch the pi off/on!
/MacValley