look:
I use swish-e to search my site portaltaurino.com

for example:
i search for:
Abellán
http://www.portaltaurino.com/cgi-bin/library/searchindex/query.pl?swishindex=%2Fusr%2Flocal%2Fswish-e%2Findex0.swish&detail=yes&keywords=abell%E1n

then i search for:
ABELLÁN
http://www.portaltaurino.com/cgi-bin/library/searchindex/query.pl?swishindex=%2Fusr%2Flocal%2Fswish-e%2Findex0.swish&detail=yes&keywords=ABELL%C1N&image.x=9&image.y=4

the results are different.

the command line i use is: (i search the titles, headings and ...)

$command = "$swishexec -f \"$array{'swishindex'}\" -w \"$array{'keywords'}\" -t the"; 
if ($array{'maxresults'} ne "") {
  $command .= " -m $array{'maxresults'}";
}

But my main worry is about the case sensitiveness
or is it al about the -´- 
the difference between %E1 and %C1  ???
i think it´s about the accent ...

I look into it now..

thnx.

Gerrit