The New Yorker stubbornly uses “coöperate” instead “cooperate” or “co-operate”. Now that’s an affectation.
I can’t believe that nobody else has called IC on “behove”. 
I am thus far unsuccessful in finding a site which gives the complete conjugation, but IIRC, the only form which uses a single “o” is behoven (past tense, but it may be more than simple past, given how old this flinkin’ word is) 
A bit more tracking, and I came up with what may be the closest to a root that Middle English has for it. However, that seems to put it in the same category as roof, hoof, calf, wolf, and (glory be!) belief.
My own particular frustration WRT to the evolution of usage is the near-banishment of the proper plurals of most of these words. IMO, given the weird behavior of the language commonly known as English, this set of phonemes deserves its own version of “Gravity: Not just a good idea; it’s the law” (or however it reads). There was a very good and logical reason for substituting the voiced letter for its unvoiced companion when pluralizing (my contribution for the day to the abominable practice of verbing nouns). :dubious: There may be others who maintain that it’s easier to say “hoofs” and “roofs”. I suppose I should be thankful that no one seems to be attempting to foist “calfs” and “wolfs” (which would, IMO, inevitably progress to “woofs”. Now I usually enjoy puns, but that would be truly putrid). :smack:
I started to compose this post when the Board froze up on me (Thursday afternoon?) and next time I tried to logon gave me the SDMB’s version of the BSoD.
Wait… hate to go off topic but I just punched in alt 1026 ( my birthday - what the heck) and got a friggin happy face . is there some master directory of these things?
I suppose that an OP that was predicated on a nitpick was somewhat destined to go careering off topic. Anyway. Behoove is a US variation of the English behove. *Colour * me Anglo. 
If this is fair reflection of the debate, then I say a pox on their houses!
Personally, I use two hyphens (or an em-dash, depending on the capabilities of the word processor) with spaces surrounding it. Like this – you see? I do that because I discovered that back when I did it with no spaces–like this–some reading programs would refuse to do line-breaks on the em-dash or the double-hyphen, and it would treat the two words as one.
And then some reading programs had really crappy search algorithms that, when you checked “find whole word only,” would be smart enough to accomodate words with . or ? or " or ! or , next to them, but not the double-hyphen or em-dash.
So, to summarize, the only time I ever don’t put the spaces around the em-dash or double-hyphen is when whatever I’m writing is going to be used solely in printed form – if it’s going to be distributed in electronic form, I leave the spaces in just to be safe.
Well, that was a fun and pointless trek.
Start - Run - ‘charmap’