Accordingly, the appeal committee dismissed the appeal and upheld the suspension imposed on the player of 12 weeks.
The appeal was against the decision of the original independent judicial officer which found the Leinster openside guilty of an act contrary to good sportsmanship in contravention of Law 10.4 (l) in that he made contact with the eye or eye area of London Irish lock Nick Kennedy in the Heineken Cup encounter at the RDS on Friday, October 9.
Under IRB Regulation 17 and the ERC Heineken Cup Disciplinary Rules, the recommended sanction entry point for a low-end offence of contact with eye or eye area is 12 weeks.
The suspension rules Jennings out of contention for next month's Ireland senior and 'A' international matches, while he will be banned for three of Leinster's Heineken Cup pool games, including last weekend's trip to Brive, and five Magners League ties.
Commenting on the decision of the appeal committee, Leinster coach Michael Cheika said: "Leinster Rugby are mystified by the decision and the whole process because we still maintain that Shane wasn't guilty of anything.
"To be cited in the first instance, it requires the incident to warrant a red card, but it didn't even merit a penalty, never mind a red card.
"Unfortunately the disciplinary officer wanted to pursue the matter even though there was verbal and written testimony from the London Irish player stating that he 'over-reacted'. We are at a loss to understand why this decision has been made.
"We're more concerned at this stage with the player as both his career and his reputation have now been tarnished.
"We will be standing by Shane during this difficult time and I know that he will emerge stronger from this disappointing judgement."