Yes, i'm using oxygen-gtk2 and that's the problem. I solved it following post 11 directions. I was looking for some KDE option that could solve it under "windows behavior" settings but the proper setting wasn't there, i have to know better my kde (or maybe kde could put every "windows...

While trying to create a guideline, the inkscape window gets resized automatically making impossible to create any guideline. This is not a inskcape bug , i'm able to create guidelines in linux using other DEs or Windows, but maybe some Inkscape/KDE4 users may have experienced this problem. I've tri...