It was quite weird to purchase slaves from this lady (http://www.uesp.net/wiki/Morrowind:Savile_Imayn), and, when talking to them, see the usual "I don't think we have been introduced, outlander. How can I help you?" greeting. I really don't think that this is a greeting a slave would use to his master who has just purchased him. Now, generic dialogue in Morrowind often clashes like this, however, this was a bit extreme for me.
EDIT: Issue resolved, problem identified.

I appreciate the input, but
I appreciate the input, but these characters should already have special greetings after player buys them. I assume it didn't work for you? Which one have you bought?