Is staying more than 90 days possible for swiss citizens ?

Hi everyone,
I am planing a trip to Brazil very soon, but i'm still very confused about the stay renewal situation. I read on the webpage of the brazilian consulate in Zurich and Geneva that i was, but on the web, many people from France and Germany (among others) where saying the contrary...

I read on this forum, that the daycountdown would not be interrupted in case of a trip to a neighbooring country.

So, i would like to know what the uptodate situation/practise is:

1) concerning the renewal of the 1st 90 days permission,
2) and the days countdown when leaving the country ?

In order to know weather i can keep my 4 months ticket or shoud make it 3 months.

Thanks in advance for your help.

Nico

Nico,
Believe the Consulates.  The EU has a 90 day, no extension agreement, but individual countries' agreements trump that, even for EU member states.  The Consulate websites should reflect the agreement between Brazil and Switzerland.
If you leave Brazil, your day count DOES stop, and starts again when you re-enter.  However, for this to happen, be sure to go through Passport Control going and coming.  This is automatic in an airport, but some of the land crossing points may be more lax.  If your departure and reentry aren't recorded by the Federal Police, they'll probably assume you were in Brazil continuously.
*ETA*  The website of the Brazilian Consulate General in Zurich now says 90 days, no renewal,  for Swiss citizens, i.e., same as for the EU.