Hi, I have a problem when using stream class from iostreams library. I have created a device class say GDevice using ios::device_tag and ios::input_seekable tag. In GDevice I 've declared and implemented read function inside GDevice class. I also create a stream class let's say GStream which derived from ios::stream<GDevice>. The problem was occured when I created object from GStream and call GStream's read method directly to read say n bytes data. The read method invoked GDevice read method not in n bytes data but always in 4096 bits. I dont understand where this number came from. I'm using boost 1.33, gcc compiler version 4.0.2 under x86-64 bit suse linux. Can somebody help me? Faithfully yours Hendra Hidayat Geophysical Lab. Natural Physics Dept. Sepuluh Nopember Institute of Tech. __________________________________ Start your day with Yahoo! - Make it your home page! http://www.yahoo.com/r/hs