i'm using zenphoto 1.2.4 with modified default theme. i feel it is very slow, i have checked some pages, it took 29 seconds or some thing related.

http://gallery.southdreamz.com/actress/trisha/awesome-collections/actress-trisha-hot-pics-08.jpg.html
in page source it shows: <!-- Content generated dynamically in 29 seconds -->.

have you tried this with unmodified themes? This is not normal behavior.

i will check & let you know!

Also see what happens if you disable the static cache plugin.