Well, this happened to me too. You don't really need the ubuntu installer to recognize the windows in order to dual boot.
What I did was to wipe off the windows efi partition (system reseved files) that was somehow formatted in ntfs and format it with FAT and install ubuntu on a separate partition using this new FAT efi partition.
Then load the windows recovery cd, and manually add on the efi partition, by using the command prompt, the windows boot files. Here is a guide on how to do that: http://superuser.com/a/504360
Procedure pretty much amounts to pointing where your windows partition is, mounting the EFI partition, and running
bcdboot to create the bcd boon on EFI in microsoft's folder.
Then to make sure when you reboot into ubuntu to install
boot-repair it will fix most GRUB and boot errors.
...or try to play around with GPT partitioning like the other answer indicated. It's fairly tedious IMO, but hey, this is Linux. :)
Best of luck!