The reason Skype won't install -

if test $REL1 -lt 1 -o $REL2 -lt 2007 -o $REL31 -lt 42 -o $REL32 -lt 19; then
blah blah blah
exit 1
fi

in preinst

i.e. 44 is NOT less than 42 but 4 IS less than 19