I installed gallery through the fantastico interface and I am unable to get an of the thumbs to actually generate. I did a bit of digging and it seems that the software is unable to find imagemagick on the server.
I have tried the folowing
/usr/bin
/usr/bin/convert
/usr/local/bin
/usr/local/bin/convert
/usr/local/bin/
I am on the Hansolo Server is that helps