Started Googling a bit on Ad-hoc connections and here are some thoughts to consider:
- you have to manually connect to the printer each time you want you print by going into the wifi settings on the iPad and choosing the printer as the network. By default, some wifi printers actually turn their wifi radio off after a period of no connectivity. Not sure about the one you have.
- by using Ad-hoc mode, you cannot print straight from a web page because you need to connect the wifi to the printer to print. Not sure if already having the Safari page open helps or not with that.
In summary from my lunchtime google, if you can get your printer set-up Ad-Hoc, select the printer's "network" in your wifi settings on the iPad, it just might work. For reliability though, I'd investigate getting a portable wifi/3G device that can create a wifi network and have both the iPad and the printer connect to that. I think it would work more seamlessly and not take up too much space.