When you say to check the clutch adjustment, there is only 1 that I know of: the lever that pushes out the throw-out bearing to disengage the clutch. Is that what you refer to?
Yes, that what he means. If more travel is added to the clutch fork and you still have this problem, then the throw-out bearing is dragging on the input shaft. That means you'll have to pull the trans and take a look at it.