Calf synth losts sf2 file

Hello, Using Ardour 4.7.0 from kxstudio under ubuntu 14.04.

Sometimes, when I reopen a session, I must reassign every sf2 file to every midi track, if it is using calf fluidsinth. But it does not happens with all files, just with some.

After several tests, I have remarked it occurs only when the file has a non-ascii caracter in its name, so by a change name it seems to be fine. In fact, I talk about “Ĉ”, i did not check every non-ascii caracter.

Is it a bug or is a mistake in the configuration?

I put it under “Linux”, because it is my OS and, perhaps it is not an ardour issue, but a OS issue. Feel free for moving it.

Thank you very much.