My sarge freezes for about 1minute in the middle of the boot, and don't type anything just black screen and a blinking cursor, fist message that I see is is something about PORT MAP and than it boots up correctly. I checked log file and see something strange
Nov 2 23:46:57 local host kernel: RAM DISK: Loading 4316 blocks [1 disk] into ram
disk... |^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^
H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-
^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H
/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^
H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-
^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H
/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^
H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-
^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H
/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^H|^H/^H-^H\^
H|^H/^H-^H\^H|^H/^Hdone.

What could It mean?
What for this ram disk is used ?
Any ideas, what to check or to do ?

The message above is normal. Its loading the kernel into the RAM to make a virtual drive in memory which is faster than using a hard drive to boot the system. Thereafter it starts implementing the services. The load time will be determined by the size of the kernel, speed of the ide bus and the system bus and memory latency.

..... I just remembered that, this freezing began after my attempts to setup Canon i250 printer, I downloaded drivers (CUPS driver and some other linux stuff) from official site and compiled them, now I can see my printer in CUPS (http://localhost:631/) but it still don't print and don't not give my any error messages.
So maybe my problem lies somewhere deeper, maybe it is connected with USB support in my kernel or something like that, any way my usb mouse works correctly :-(

This could well be a hardware based problem. It is unlikely to be the kernel as such but more of a problem polling the device. I have seen similar problems in the past when detecting new networking parameters.

I don't think that the problem is in hardware because it works correct in windows

Well there is a very simple test. Disconnect the printer and see what happens. If the boot time shortens you will know whether the printer is causing the problem.