Christophe,

When I have encountered this problem before I have ultimately discovered it
is a logic issue. One must be careful when using the AND vs. OR choices.
Currently I have a form in which all the submission buttons require all
required fields to be filled in. This currently is about 12 fields. Then
each button must also determine workflow status by reviewing a list of
Boolean flags which account for about 10 more fields. While I haven't hit 50
fifty yet some of them were truly tricky. The easiest way to approach this
is to model the requirements. You may also find that using flags instead of
the forms fields may allow you to combine some of the requirements.
Basically as you go through your logic you need to test each of the
possibilities as you add them to the rules. Don't wait until all your rules
are in place as that it makes it much harder to debug. Run the preview mode
often and check your validation that way.

Hope this helps.
"One Line at a Time"

Greg McAllister