Fluttery hydraulics.

[alan s]

I did an LHM change/filter clean in the Xantia '94 VSX.
Everything went well until I reassembled and started. Car raised very quickly; I set it to the highest setting, then the lowest and then the highest again in quick succession.
When I set it back onto the highest, it started fluttering the warning lights at me and the buzzer was keeping time with it. I don't mean the normal "heehaaw" type warning, this was actually fluttering; the light wasn't going fully off or fully on; it was just like something with a loose electrical connection.
At first I thought that perhaps the suspension being in normal mode may have given a clue as it seemed to stop it in sports mode, but then I topped up the LHM and tried again & this time it also did it in sports mode too although it doesn't seem to last as long in sports.
On it's worst display, it kept fluttering and whingeing at me for about 20 - 30 seconds before I gave it a rev at which time the fluttering sped up before the lights went out & returned to normal.
I also noticed that when I loosen the bleed screw at the accumulator that it doesn't do the usual hiss/thud yet I noticed bubbles in teh LHM tank. Not as many as I expected but a few. Jubillee clips have already been fitted to the supply & operational return lines.
Any body ever struck this fluttering caper before?
Alan S