I've somehow managed to compile xine-lib-1.1.13 using mingw on windows (patches for build fixes will follow soon).
muxine.c (without the x11 part) crashes in xine_get_pluginroot() in line 400 which was recently added with the comment "... completely untested". :)

in xine-utils/utils.c:
396 char *sep, *sep2;
397 strcpy (pluginroot, xine_get_plugindir ());
398 sep = strrchr (pluginroot, '/');
399 sep2 = strrchr (pluginroot, '\\');
400 *(sep < sep2 ? sep : sep2) = 0;

for me, the xine_get_plugindir() gives "c:\lib\xine\plugins\1.2"
if the path does _not_ contain both '\' and '/', either sep or sep2 will be NULL which
leads to a segfault. (I guess the compare operator should be switched.)

however, on linux, xine_get_plugindir is just hardcoded to something like "c:\lib\xine\plugins\1."

should the dynamic xine_get_plugindir retrieve " "../xine/plugins/1." ?

This Changeset http://hg.debian.org/hg/xine-lib/xine-lib?cs=5d01b16fcdfe;style=gitweb
suggests something along this lines.