I downloaded volumes 1-9 just before the holiday break (I've read them all on the web before), and in my re-read, I'd gotten to, oh, volume 5 or 6 before making this discovery.
Recently, disaster struck! Only ten minutes into the gym session, I finished volume 7 and… volume 8 wasn't on the iPad. Oh noes! Since I've read them all before, I could just continue with 9, but still - eak!
Luckily, it turned out that the download just came with a different filename, so I missed it when importing them all into iTunes. Problem solved! Phew.
1 If you're not familiar with the multi-Hugo-winning Girl Genius, it's a web comic that is released one full-colour page at a time, on Mondays, Wednesdays and Fridays. It's a "Gaslight Fantasy" with the tagline "Adventure, Romance, Mad Science!" It's top-notch, cracking stuff, with a great list in characters and a witty turn of phrase. And lots of slapstick in a manner I find reminiscent of the better Xena comedy episodes. If you like comics, just go read it. Now.