get stream position

i create a new stream, open an xml file for read,
and use myDataSet.loadXml(mystream)
now, on a separate thread, that runs only while the dataset is being loaded i keep printing stream.getPosition to the screen.
it goes
0
0
0
18234
18234
...
and then it does 18234 about 50 times.. 18234 is the length of the stream.
i guess this has to do with buffering or something, but how the hell can i get the actual position that the stream is being read from, avoiding this error?

any ideas? maybe i should use different objects and methods??

thanks already...

Show us the code.