I did try pushing the strut down by hand,but the roof wouldn't stay down for long. The gas struts seem to be the way to go-bit sceptical about "recalibration"- sounds like dealer speak for just fiddling around with it! Hope you don't lose faith in yours.
Possibly a different issue then. Once my strut is forced into position it's locked solid, no chance of any movement.
To be fair to the dealer they did fix it, just over time the shear bulk of the roof mechanism causes it to run out of alignment, at least in my case, and that does sound plausible.
It's still never needed any new roof parts in the 5.5 years I've had it, but labour rates are bloody ridiculous.