I agree Manitas, I always make an effort to note which side of the path the cycle lane is.

I think one of the problems is that when they divide down the middle what was once simply a path for foot traffic (as most cycle/footpaths are) planners seem to fail to take into account the ratio of heavy foot traffic, to light cycle use. On most paths in town where there is a constant stream of pedestrians - often families walking together - you'll get an individual cyclist now and then. Families and couples usually walk together two or three abreast, while by comparison cyclists usually cycle solo in single file. The space allocation on split footpaths rarely seems to represent the disparity of volume of usage by pedestrians v's cyclists. Thus pedestrians tend to spread into the cycle lane. Another problem I've found is that unless you're continually alert to the signs on the floor (and unlike when cycling, while walking I rarely look at the ground) you can be walking on the path one minute, turn a corner, and you're inadvertently walking on the cycle lane without noticing that it's just swapped sides.