plugphasor~ vs "plugstaircase" in PT LE

hi,
a quick search in the archives didn't show up anything useful, so i
ask here:

using plugphasor~ in protools LE doesn't give a smooth ramp, but
rather something like a staircase...
( osx 10.4.4, pluggo 3.5, pt LE 7.0 ) and ( osx 10.3.9, pluggo 3.5,
pt LE 6.4 )

while the same pluggo in live ( 3.0.2, ich weiss, uralt ) works ok,
i.e. no staircase.

does that sound familiar to anybody? is that just the pathetic
support of host syncro in protools?

thanks.
volker.