(I should point out that most of my interactions with management teams are professional, collegial and, over time, become very friendly. There are outliers though...)
1) When the company CEO sits in my seat at the head of conference table. If he acts like my office is his, how will he treat my investor's money?
2) Inability to drop the damn script! Back when I practiced medicine, I used to read my patients' medical records before their first appointment; that way the patient didn't have to waste too much time telling the same story that she had given a dozen other doctors before. As a PM, I read a company's filings and try to review the management presentation in advance and like to go straight to my questions. Usually this works well.
Except when it doesn't, and the CEO gets all flustered, or worse, annoyed or angry (it happens) that I had the temerity to try and wrest control over the meeting from the company.
3) Refusal to answer a really basic and important question. Like "what is your expected cash burn?" Yes, I guess you can get away with "we haven't guided to that" but then again you can get away without my fund investing in your company. A delightful variant is "the proceeds from this raise will get us into 2015" type non-answer. Does "get us into" mean you run out of cash at halftime of the Aloha Bowl? Chinese New Year? Thursday of the JP Morgan Healthcare Conference? Second round of the NIT? Come on -- you are asking for millions or tens of millions of my investor's money -- give me a straight answer.
4) When the chairman of the board comes to the meeting and keeps interrupting and correcting the CEO. That leaves a great impression.
5) I saved the worst for last: when the company brings lunch for PM and the analyst and forgets the office staff.
Follow Luke Timmerman and Xconomy on twitter: @ldtimmerman and @xconomy.