Library compatibility issues under Visual Studio 2005 in Debug

Hi,

I just download 4.6.16 and compiled in Release and Debug for Win32.

When I use the Release DLL all is fine, but when I use the Debug DLL I
get GPF at:

EnterCriticalSection( &(((_FILEX *)pf)->lock) ); in file.c.

when calling set_feedback();

I am use to getting his (although I don't know why) so I compiled the
static library. When I compiled the static library (Debug) I now get
this assert:

2007-08-03 13:15:25 assert failure: ..\env\env_alloc.c/335: "p[elp-
>ulen] == GUARD_BYTE"

I have tried compiling with "MiltiThreaded Debug DLL" and
"MultiThreaded Debug" and it still won't fly.

Any help greatly appreciated.

Gerard