Hi, I have a problem when using stream class from iostreams library. I have created a device class say GDevice using iostreams::device_tag and iostreams::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 iostreams::stream<GDevice>. The problem was occured when I created object from GStream and call GStream's read function directly to read say n bytes data. The GStream's read function invoked GDevice's read function 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. __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com