New Asus n56vm laptop with an SSD (Samsumg 830) installed instead of the HDD it came with.

Ubuntu is the only OS installed on it and its installed in EFI mode.

The problem is that it will boot maybe 9 out of 10 times if an USB device (such as a mouse) is connected before powering up. If no mouse then it will 9 out of 10 times hang right after the grub menu (saying "Loading initial ramdisk").

No logs are being written to /var/log so there's nothing to google on, I've experimented with with booting into rescue mode, setting/unsetting several grub flags (noacpi, disable graphical boot etc) but nothing has worked so far.

In the bios I can see 2 boot options of the SSD (2 Ubuntu with identical names). Booting of the second in the list reverses the issue above (9 out of 10 times it will boot without the mouse attached).

I've tried this fix: which kind of touches on the subject, but did not solve the issue.

I ran Boot-Repair on it, and when I did a third boot option off the hard disk appeared, but still the same behavior as above occurred.

Do you have any hints about how to solve this?