A CRJ-700 Captain reported discrepancies between the ILS glideslope signal and the VASI for Runway 34 at AVL; advising the ILS glideslope signal commands an excessively steep descent and a threshold crossing well above the charted TCH.

Narrative

We were assigned the visual approach to Runway 34 into AVL. As per our POH we briefed the ILS to 34 and had the localizer frequency selected for the ILS 34. If you follow the glideslope to Runway 34 the VASI shows all white. It can be confusing coming in to land with the VASI showing such a huge discrepancy. I believe (just by looking visually) that the glideslope is way too high. I would say that the glideslope touchdown crossing height would be around 150-200 FT. It is my understanding that my takeoff landing report is predicated at having a touchdown crossing altitude of 50 FT and touching down in the touch down zone.Up until the last few months the glideslope and VASI have always coincided. I believe that the VASI is the correct approach path. However the glideslope has you landing long.I questioned the Tower about the glideslope and VASI not coinciding. The Tower said they have had numerous complaints over the last 6 months; however the FAA says that it is normal.The FAA needs to check the ILS to 34 and correct the problem. The approach plate for ILS 34 should at least say that the VASI and glideslope don't coincide (however I think there is such a huge discrepancy that it needs to be fixed).