I trained maybe 4 or 5 times in a row for Speech with Ogmund in Markarth (I trained 5 times, then leveled up, and repeated this cycle four or five times in a row), and after that there is no longer a dialogue option to train me anymore. I went to another trainer (Babette, who I know trains Alchemy), and she allows me to train. However, I noticed that none of the people at the Mage's college have the option for me to train either. I thought I remembered them having the option.
Is this a bug, or is there a limit to the number of times you can train with a particular trainer?