They are stored on the external SD card, which is the one that is plugged in to the phone. the "ext_sd" path gets you to the external card. The rezound's internal vs external SD cards is confusing!
When I connect to the PC, I can see two Storage Devices.
One is HTC STORAGE, which is the Internal storage, the other is just a plain Removable Disk label which is the External card storage.
No HTC storage on mine. I ended it all by uploading the pics to picassa, then down to my pc. Deleted the phone content and made sure that the photos now save to the SD card.