How come I can't get this to work? I opened some tables on Party, ran the FreePHG executable, but it's not creating any .hhf files in the directory.
How long did you wait? It uses the first hand it sees at each table as a reference hand and won't write it. It does this so that it knows new hands at that table will have a higher hand number, else it can end up writing a corrupted 1st hand.
Also, are you using version 0.01 or version 0.02? Version 0.02 outputs some information on what it is doing by default (whereas v0.01 needed the -v option using, else it just displays a blank screen).
Only other reason I can think of is that you system is under very high strain (FPHG uses a lot of CPU to poll memory, and if the system is under high load then it wont get enough CPU time to scan for hands).
EDIT: Also try restarting both FPHG, Party and iWitness. I did one night leave it all running and woke up with no hands at all (but wasn't sure if I forgot to run something or if the party servers had gone down seconds after I went to bed...). So their could be something like this happening on rare occasions.