There are two timebases, primary and secondary on the transport bar each of which can be selected to be either Bar, Frames, Samples or seconds.
Also there are two rulers, one present always by default and the second can be enabled via the ruler track introduced in v5.
The way S1 currently behaves is that the timebase for all 4 i.e. the primary and secondary timebase for transport bar & the primary and secondary timebase for the 2 ruler tracks can all be independent of each other. So if you want, you can have the primary transport bar timebase set to BARS, secondary transport bar timebase set to FRAMES, Primary ruler track timebase set to SECONDS and the secondary ruler track timebase set to SAMPLES, or any other possible combination of the 4. Now, this might be useful in certain rare instances.
However in most cases i reckon, people (including myself) might want the primary transport bar timebase and the primary ruler timebase to be the same and the secondary transport bar timebase and the secondary ruler track timebase to be the same. Hence an option in the global preferences to check/uncheck such a behavior could be very useful. Something like "Sync Transport and Ruler timebases"or something along those lines. Hope this gets implemented sooner than later. Please make it happen Presonus.