I have a fix for this in the development codebase, ready for the next release. If you want to take it sooner than the next release (I don't have any prediction right now for when that will be) then you could patch the sourcecode in the 0.3 release package and build it yourself, if you have a dev environment.
Change the definition of standardkeys in osk_out/osk_out.c (about line 135) to:
// Note: \001 indicates a char we can't type directly (e.g 'multiply').
char * standardkeys[4][3] =
{
{ ".,!?@\"'`:;()<>[]{}1", "abcABC2", "defDEF3" },
{ "ghiGHI4", "jklJKL5", "mnoMNO6" },
{ "pqrsPQRS7", "tuvTUV8", "wxyzWXYZ9" },
{ "", "/-~=_*\001\001+#\001\001$\001\001\001\001%&\\^| 0", "" }
};