Something became plain.
1. One of these two problems comes from the fact that memory is constantly growing, the required process "osu!.exe" in Task Manager.
2. When the process is "osu!.exe" comes to about 1GB, it becomes one of the two problems mentioned in this thread.
3. Memory begins to grow in those cases where: the player starts to play a song or list of songs scrolls player.
4. The smaller the list of songs, the less memory is added to the process of "osu!.exe".
But even when a large number of songs in osu if you select a single group (group by) and there will be a few songs, the memory will be added little because open one group of songs from all the songs that you have in osu.
5. If nothing is done in the main menu and not playing a song, then the amount of memory that is added "osu!. Exe", does not change. But if at the same time to go to the list of songs, then will play the selected song and the memory will be added exactly 10Mb.