Yes that can work against you, I learnt to switch off the Microsoft communicator to off-line status up until 9.00 though if someone came to my desk just had to accept it.
Managers are different too, some can be in at 7.30am others 8.45am and another 10.30am.
Some are authoritarian most are easy going until things go wrong as they do from time to time.
Successful ones for me need an edge, so you automatically respect them and knock on their door when their calendars are free. Normally found this worked though am also able to judge when they are stressed and know that is not the time to approach.
One manager I liked early on was in charge of about 100 people, I go on well with him as we went to the same school although about a decade apart. I recall one evening about 6pm the phones were going and I was the only one there, he came out of the office and picked up a phone and dealt with it.
When I wanted a move he told me straight he didn't think I could get into that area of the company though added he didn't want to lose me.
I later moved jobs and a couple of years later moved abroad and phoned him to see if he would give me a reference, he seemed delighted. The agency later told me he game me a top reference and I got a decent job.
When I came back to the UK I went back to that company and on my first day I saw that manager walking through the corridor and nodded and smiled. I never saw him again in the office, he had just been sacked.
Bizarrely I saw him five years later at a school reunion and we had a chat and it was interesting, he told me he had fallen out with the client manager. By then he had risen to manage about 250 people yet had fallen out with the client manager and had paid the price. He knew it was a grey area and should have been diplomatic though for some reason he could not explain he decided to stick to his guns and let the other know in no uncertain terms he was not budging. He was philosophical about knowing it was partly his own fault.
Said he had had a couple of jobs later though added they did not last long this was about 2005.