Timex Run Trainer and Intervals (Read 17 times)

Just got myself a brand new Timex Ironman Run Trainer GPS

It comes with an option to set up several workouts and all that stuff, but I can't figure out the logic of that. I am used to Garmin and Suunto, in the latter (a T3C) I was only able to set up intervals on time, in the Garmin it's either time or distance: interval, rest, warm-up and cool-down, pretty intuitive.

In the Timex I get to the menu and find: Warm-up (ok, understood), up to 5 intervals and a cool down. The there's reps. The intervals can have pace, distance etc, etc... but you need to set a time for them else they won't appear on the watch... or at least that's what it seems to me. The logic of setting a distance AND a time escapes me totally.

I tried to make a 6x100m strides interval after an 8km run (at aerobic pace).  I set a warm up to 10 seconds (just to set something), I then set up one 100m interval setting the timer to 3 mins just to set something even it it's ridiculously high, the second interval should have been rest of 30 seconds... it became a total chaos! The interval did not finish after 100m but continued happily ticking until I hit the SPLIT button. Annoying as hell. And then there was a beep that I have no idea what it was trying to tell me (still have to figure this out).

Does anybody have an idea on how I can set up something like a simple interval:

Int. 1 : distance (NO TIME)

int. 2 : rest time

I can live without a warm-up and a cool-down

Thanks mates