This is not a bug in itself.  I noticed that compiling xfmedia 0.9.2 without any optimization flags (all -f and -O options turned off and replaced by -O0) enabled the player to set the size of the video window correctly.  When xfmedia 0.9.2 is compiled with the default optimization flags (-O2 -fno-strict-aliasing), the player cannot set the size of the video window correctly.

A list of all warnings (some are a bit pedantic) when compiling xfmedia with the below flags can be found at the supplied URL.  Some however seem more serious and can hide real bugs.

Compiler: gcc 4.2.1
Flags: -W -Wall -ansi -pedantic -Wbad-function-cast -Wcast-align -Wcast-qual -Wchar-subscripts -Winline -Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wredundant-decls -Wshadow -Wstrict-prototypes -Wwrite-strings