There was a small issue at work. I solved it and notified my manager over IM. She said, 'Thanks, Vinay'. I replied her, 'Anytime' as I do with my other colleagues and friends.
A colleague of mine sees this conversation while working along with me on the issue and gets surprised and says, 'Anytime!? Even to our superior!?'
Another colleague advises me not to repeat this again and tells that weren't supposed to say that way.
I'm confused. Is it really something important from my superior's perspective? Will this give the wrong impression? If it's so, what would be a polite way to reply other than a formal 'Welcome'?