Weird thing just happened. I couldn't suspend on my #linux laptop because of sftp-server couldn't be frozen. After executing `echo w > /proc/sysrq-trigger; dmesg` it showed me #FUSE (Filesystem in Userspace) as possible culprit!? So I had an idea since I keep an local #ssh connection open via nautilus(/#gvfs), I tried to unmount it, and it told me multiple sftp-server were using it.. After force-unmounting it, suspending started working again! Good night.