Overlapping Regexps

[Bill Denney]

When running the following,

frag = {"MGTGGR" "R" "GAAAAPLLVAVAALLLGAAGHLYPGEVCPGMDIR" "NNLTR" \
        "LHELENCSVIEGHLQILLMFK" "TRPEDFR" "DLSFPK" "LIMITDYLLLFR" \
        "VYGLESLK" "DLFPNLTVIR"};
seq = strcat (frag{:});
cuts = regexp (seq, '[KR][^P]');

the result is
cuts = [6 41 46 67 74 80 92 100],
but I expect for cuts to also find 7.  In other words, I expected
cuts = [6 7 41 46 67 74 80 92 100].

On a related note, if there is overlap in matches, is there a way to 
make regexp return the overlapping matches?  For example:

a = "ababababab"
b = regexp (a, "aba")

returns b = [1 5] when I would like for it to return b = [1 3 5 7].

Is this a bug in my understanding of regexp or in regexp?

Thanks,

Bill