[sdiy] S D Mosfet swap

[Gavin]

Anyone know if it's ok to swap Source and Drain on a MOSFET like those in
the 4007?  Datasheet-wise it seems like it should work, I mean using the
drain as an input and the source as an out, but the circuit (Rene's
excellent CMOS VCF design) isn't working properly and I'm wondering if I
should continue troubleshooting or just re-do the layout with them the right
way round.
Thanks,
G.