I have noticed that my seat height adjuster 'deflates' over time and despite doing a search I can't find a fix for this. I wondered why I always finished a journey feeling about 6 inches shorter than when I started  Cheers,
Raz
FL1 TD4 GS Auto 2001 Silver
FL2 TD4 Auto 2007 Black
FL2 XS SD4 Auto 2012 Fuji White

I knew it was on here somewhere.

http://www.freel2.com/forum/topic7548.html?

This was a problem on 2008 models and they had new seat bases fitted undr warranty.
Also check: if you are using seat at full height it is possible you are moving lever down every time you exit car, it happens with me regularly 2011 SD, I can do a 200-300 mile journey without any drop in seat height but it is down after shopping trip when out and in car 5/6 times. All FL2's (3) Gone
2011 Mercedes C180 CGI Gone
FL2 GS Auto SD with heated leather, factory tints, alloy spare and a few other bits.

Same problem here, as you get in/out of the car you sit on the lever and lower the seat without realising.
Doesn't happen on a long journey though with mine (2011 model)

Taz

same on my old 07 model.
at first i thought it was a seat issue, went to dealer a number of times, in the end they upgraded the seat to an electric one.
but just before they upgraded it i found out that it catches the underneath of your leg when exiting the car! Anyhoo off oot on me mobike.....