In 2.49, you could adjust the maximum length of Auto-IK Chains by using scrollwheel up/down or page up/down while moving Auto-IK bones. Now this is possible again with those hotkeys, but you need to hold SHIFT to get this to work, otherwise we get a conflict with the hotkeys for proportional edit nowadays.
Was broken when transform tools switched from using hardcoded key mappings to using a modal keymap.