Only have thumbnails, not originals

[Dianne Reuby <pramclub yahoo co uk>]

I'm running F-spot 0.3.5 on Ubuntu 7.04, and I'm fairly new to both, as
I switched from XP in April.

I copied my photos over from XP, but now the main photo directory is
empty. I can copy them again from XP, but I've obviously done something
to loose the originals (I haven't deleted them with Nautilus) and I'd
like to work out what I've done.

I've applied tags to the thumbnails, and I've also installed Picasa, so
that may have done it. I plan not to use Picasa, so I'll probably remove
that.

Could Picasa have caused the problem, before I start again?

TIA
Dianne Reuby