I can think of two possible house rules that might fix the problem.
One is to combine the ready and delay actions. We eliminate the ready action from the game. Instead when you delay, you set conditions to trigger it, and when it goes off, it follows the current timing and initiative rules for readied actions (ie - it's an immediate reaction, your initiative is set to immediately before whatever you react to, you can interrupt movement etc). The problem raised in this thread goes away, because you can't ready part of your turn.
It makes readied actions a bit more powerful (because you're doing more with them), but at the same time it reduces the game's complexity by eliminating the difference between ready and delay. It also reduces the amount of... um... "context switching" - ie: how often players start and end their interaction with the game, which should speed play slightly.
The other option is to say that end-of-turn effects end when they are least beneficial. Ie - buff-type end of your turn effects inflicted by or on you cease when your normal turn ends and also when you take the readied action, but saves and penalties that last until the end of your turn are taken after you perform the readied action. That seems a lot more complex though.