OK, I just traced the problem of amule segfaulting on start. It all seems to happen because of a bug in aMule (which strangely it doesn't happen on another platforms). It's (from what I read) some kind of race condition, no idea where. Compiling with debug enabled fails on my solaris, amule won't link, therefore I can't produce backtraces. The important thing is that I just discovered that removing blastwave's libxcb (CSWlibxcb package) aMule compiles and works fine. Now, the problem with that is that removing that library breaks blastwave's gd library, which is needed by amuleweb (there's no complete happiness, uh?) so the solution would be compiling gd from source. But that's also troublesome. I'm still working on this, and as soon as I get aMule compiling and working completely, I'll post it here and update the wiki.
On unrelated news, upnp is broken on solaris, since it will return UPNP_E_INIT_FAILED on aMule startup, and ports are not open on the router. I'm no developer, therefore I think I cannot solve this, but any clue about it will be welcome.
Regards.