its always danced like its spoken
dont mistake the lenght of a beat and the beat count.
the lenght is the time between two counts.
a common rythm pattern for latin dances is:
a & a 1 a & a 2 a & a 3 a & a 4
1/4 1/2 3/4 1 5/4 3/2 7/4 2 9/4 5/2 ...
1/4 1/4 1/4 1/4 1/4 ...
the first line is the spoken counts, and the second line are the time between start (0) and the count.the third line is the time difference between the counts
walt chasse timing 1 2&3 is: 1 full beat, 1 full beat , an half and an half. but there are a lot of common syncopations allowed in walt, i.e. :
&1 2 3 for running left turn (1&2 3 is common,too)
or templturn 1 2&3&
while looking to worldchampions you will recognice that they dance sometimes chasse with the rythm &1 &3 or even &1 3& .
so you can dance like socialdancers interpretation of chasse 1&2 3,too.
be creative and play with the music 
Samba basic rythm 1a2 is a little bit more tricky
1 full beat, a quarter beat and a 3 quarter beat.
a variant is the volta timing 1a2a3a4 . dancing Criss Cross 1a2a3a4 1a2a3a4, a common biginner failure is not to dance correctly beat 4 , its longer than the others, there is no "a".
An other possible Samba rythm is 1&2 or &1 2, 1 full beat and an half and an half. (counted: slow quick quick [or quick quick slow]) used in i.e. Rocks
A absolute different rythm variant of Samba is used in running promenades. (there exist a variant of the running promenades with q,q,s rythm,too)
the counting is 1,2,3 on 2 full beats. there are different opinions about the rythm interpretation of this syncopation, but its not &1 2(half,half,full). The variant popular in germany is 3/4 beat 1/2 beat 3/4 beat or 5/8 beat 5/8 beat 6/8 beat.
there are a lot of possible syncopation in Samba
listen to a rythm only song ...
There are some other ideas about rythm interpretation, too. i.e.
In CCC the basic rytm is 4a1 2 3. you can dance it like: full beat(4),half beat(a), half beat(1), full beat(2), full beat(3) ...
but if you take a closer look on top couples they mostly use a slight differnt timing, the "and" wanders closer to beat 4, so that there is more time for beat 1 . If listen carfully to the music you hear that the "and" isnt exactly the half, ist more a "third"
there are similar opinions about the chasse in walt, too. so I ve heard differnet opinions from different trainers & couples. One told me that the "and" is more closer to beat 2 the next told me that the "and" is a little bit closer to 3. I choose the second variant, because my feeling is it fits better to the music.
Its music, not mathematics , so dont care about "unround" numbers 
a common rythm pattern for latin dances is:
a & a 1 a & a 2 a & a 3 a & a 4
1/4 1/2 3/4 1 5/4 3/2 7/4 2 9/4 5/2 ...
1/4 1/4 1/4 1/4 1/4 ...
the first line is the spoken counts, and the second line are the time between start (0) and the count.the third line is the time difference between the counts
hope this helps.
[This message was edited by curl on 08-26-01 at 03:29 AM.]