The problem: when I rotate a guide in Illustrator CC and then want to move that guide while zoomed way in (+300%) I am unable to select the guide. Annoying? Most definitely. Is it just my system or is anyone else having this problem?
Have you tried to reset the preferences (lose down Illy and press Ctrl+Alt+Shift/Cmd+Option+Shift during startup (easy but irreversible), or Move the folder with Illy closed (more tedious but also more thorough and reversible))?