If your camera menu has a 'Communication' setting, make sure you have PTP selected and not 'Normal'. I'm not sure this will work.. It's just a suggestion.
"Normal" is Canon's proprietary communication protocol. It's used by applications developed by Canon.. (The ones that came on the CD included with the camera).. The iPad won't be able to recognize Canon's proprietary mode..
"PTP", stands for Picture Transfer Protocol. It's a universal communication mode used by all the digital camera makers. The iPad should recognize this.
With early EOS cameras, you had to manually switch between the two using the camera menu... With the newer models, they autodetect what protocol the host device wants to use and do the switching for you.