PyQT, QProcess.readyReadStdout() problem

[aljosa]

part of code:

try:
self.isdnlog = QProcess(self)
self.isdnlog.addArgument("/usr/bin/tail")
self.isdnlog.addArgument("-f")
self.isdnlog.addArgument("/home/aljosa/qt/isdn.log")
[...]
QObject.connect(self.isdnlog, SIGNAL("readyReadStdout()"),
self.onPhoneCall)
self.isdnlog.start()
<<<

problem is that isdnlog logs 2 or more lines per call, and QProcess
moves one line per call. is there something like
QProcess.readLastLine()?

Aljosa