Consider this a potential bug report I guess. While I haven't tried it, I don't believe for a single second glib's gmodule actually works. The way the Nokia port is done, it's using the dlopen method of module loading. As you know, Symbian OS links by ordinal, so when glib tries to do something like this:
if (g_module_symbol (module, "g_module_check_init", (gpointer) &check_init))
There's no way that's going to work, because Symbian DLLs just don't have any symbolics in them for that kind of thing.
As I say, I haven't tried it, but I reckon it's a total misfeature. The gmodule config ought to be changed to use the "NONE" configuration and not waste time by actually trying to load modules.