Unless I'm mistaken, this means that and should do the same, but they don't. resets the control to the default view, i.e. only display the tick marks at the starting and ending positions. associates every increment in the range with a tick mark.After the word TickInterval, specify the interval at which to display additional tickmarks (if the interval is omitted, it is assumed to be 1).
I assume that TickInterval is meant to behave like the TBM_SETTICFREQ message, which also states something similar:
The default setting for the frequency is one; that is, every increment in the range is associated with a tick mark.