Yes, movement still provokes AoOs as normal, even while charging... The rules compendium even expresses that items in the table marked as "no" for AoO still provoke an AoO if you move out of a threatened square while performing the action.
The diagram on RC p.18 even expressly states
"Tordek charges to attack the troll. He provokes an attack of opportunity from the hobgoblin when he leaves square A (which the hobgoblin threatens). The troll threatens square B, so when Tordek leaves that square he provokes an attack of opportunity from the troll."
