Thank you for your answers. I just don't understand something. I opened 14 different html tabs in bluefish, edited them saved them, all this many times without crashing. The only time I get a crash, is when I open a .css file...
As for the memory, I use Openbox. From top I get that I have 850-870M free memory every time... I don't know what's happening.
Well, time to learn to use vim/gvim with plugins.