[SOLVED] Problems with KDE on Debian Squeeze.

Hello all!

It's my first problem with Linux. I installed Debian 6.0.4 on an old system: Athlon XP 2000 +, 512 MB ​​RAM, graphic card NVIDIA GeForce 4 MX440 64 MB.
Until a few days ago I had no problem. Then, do not know why, there were more problems. A list:

1. Dolphin starts very slowly. It just takes about 15 seconds, regardless of where start Dolphin. Once Dolphin starts, everything goes smoothly, can navigate through folders, files. But when I open a file (in Dolphin) with Kwrite, Kate, again I have to wait to open those programs to edit files.
I tried various solutions: disabling Nepomuk and Strigi, Dolphin various settings - nothing worked. But what is strange is that Dolphin starts normal (fast) when Internet connection is disabled. What can I do? I am exasperated.
2.Another problem, perhaps related to the first, is that Konqueror freezes after start. I can not open the menus, I can do nothing. Can press the Close button and then a message appears that Konqueror application is not responding. Then a forced shut.

Edit: I realized now that all KDE programs start slowly. Non-KDE programs are not affected. Also, options Logout, Restart, Shutdown from KDE Menu take effect late.
I hope I can solve these problems, otherwise use the last resort, reinstall.
I mention that I installed KDE 4.4.5 and Nvidia proprietary driver (after I deleted nouveau and nv drivers). I do not think these problems are caused by this driver, because everything has worked well so far.
I really do not understand where the problems occurred.

512MB of ram is too little for a DE like kde4. Gnome would be a liiitle better and xfce much better (if you can manage it's annoyances).

I know that 512 MB of RAM is not much, but KDE work well before problems occur.
I found something: all the above problems disappear when I disable the Internet connection.
So seems to be a problem with the connection.
Edit: I solved. I remembered that I was playing with KDE settings and then the boot messages including something like the system can not read the file /etc/network/interfaces.
I have reviewed this file and found that the wrong lines were introduced. I've deleted it and voila, everything works normally.
How can I mark the thread as Solved?
Last edit:I now realized how to make as Solved.