Hmmm.... today I ran in a similar kind of error:
CFile.cpp: In member function `virtual uint64 CFile::GetLength() const':
CFile.cpp:382: error: `_fstat64' undeclared (first use this function)
CFile.cpp:382: error: (Each undeclared identifier is reported only once for each function it appears in.)
make[3]: *** [libmuleappcommon_a-CFile.o] Error 1
Now just some more info:
I compiled sucessfully (and even working!) on 20060109 sources
I haven't changed mingw/msys component since then
I haven't installed any software on my machine
It's also noticeable that CFile.cpp has a modify date of 2006 Jan 10, and I haven't try to compile since Jan 09...
I would like to try patching the file as shown by Radek, but I am not sure about how to do it (diff output syntax is quite obscure to me). The unmodified(?) lines at pos 381 of my Cfile.cpp are
struct __stat64 buf;
if (_fstat64(m_fd, &buf) == -1) {
while they should read (if I read well the diff output)
struct _stati64 buf;
if (_fstati64(m_fd, &buf) == -1) {
The additional _ and the fstat instead of fstati makes me think that I can't simply copy the patch listed to have working code...
Someone can help me?
Linux box has already finished compiling 20060113, and until I'm able to patch this source I won't be able to control amuled... (I'll have again to stick with amuleweb)

Thanks!