I thought you just bumped an old thread with a post of a solution that doesn't involve typing accents.
In your shoes, I might uinstall a French keyboard. Not hardware, mind you, but software. I'm not sitting at my Mac so I can't recall the precise steps but it's in the same menu area as the Character viewer. THis might not work for you because for all such keyboards you wind up needing to memorize that e.g. the backslash on your English-hardware keyboard has been replaced with the cedilla.
I even looked it up online to get the correct keystrokes for the correct direction and accent. I get the accent and then the letter. InDesign is not allowing me to have the accent over the letter. Is this something that broke in CS5 and just needs to be fixed?
Probably not. Can you tell us what keystroke(s) you're using, what operating system you're using, and what font you are using? InDesign CS5 is occasionally flaky about "combining accents" but if your font doesn't have the combining glyphs I think it simply won't work. I think.
Well the font could very well be the issue, but I just tried with Minion Pro with the same problem. Font is DIN Pro. System is 10.6.8. CS5. Yeah, not sure I'd want to install a keyboard for one file. I guess it could be helpful to know about though. Usually I have 1 or 2 letters I need to put an accent on and Character Viewer work fine for that. Not super conveninet and the keyboard, but helpful, especially for those characters that you don't know.
Option + Shift + e then e again to get that accent on the e.
So you saw me on that old thread. I ran into it while looking for something to solve this issue. I had already resolved that issue, which for me wasn't an InDesign problem.
I opened the glyph window/panel, but that doesn't help with while typing. It is more convenient than Character Viewer I think.
I saw this website yesterday, but apparently didn't follow the keycomands very well. I tried it again and it worked. User error. For some reason I put a shift in there when it was just "option + e + letter to be accented".
My whole job revolves around squeezing 40+ languages into InDesign, so I'm likely to reply to any post that is at all related to non-English stuff.
Minion Pro has an acute accent, which is what you get with option-shift-e, but it looks to me like Minion does not have a combining accent, which is what you'd need. Your method did not work for me with Minion Pro, but it does work with Times New Roman. (Note that I'm not not not suggesting that you use TNR in your layout, I just picked it because it's a font that I know everybody has that also contains combining accents.) But if you use your method to type an acute accent on a font that actually has a combining accent, and then select that combined e-plus-combining-acute glyph and change it to Minion Pro, then in the glyphs menu it'll show up as a precomposed e-with-acute.
I handle a vast amount of Vietnamese text, so I run into this kind of issue all the time. You may want to look at this thread if you want to make your own special-character-input scripts, or maybe at this page of this book if you want to memorize all of the special-input key combos so you can specify e-with-acute and a-with-acute and whatever-with-cedilla directly, rather than trying to use combining accents. I think those instructions will work but I once again have to offer my at-work, no-Mac, I-didn't-test disclaimer.