Glen. I too have this issue with one of our 2009 Vibe GT's . It seems that the hydraulics that hold the seat up in the highest position (that's where mine is always, due to me being a short 5'-7" tall)leaks down, so I have to "pump it up" (no Hanz & Franz here
) usually every month or so. I just constantly check it and adjust it when it feels lower. Not bothering with any fix at the moment .