Second Turbo Boost Problem

[BleakBoy]

Hi on my Gen 3 RX7, got a wierd one,

Last night on the way home from the gym, I gave the car a little run and found when the rev\'s hit where the second turbo kicked in it didn\'t really feel like the turbo was working.

This morning on the way to work waited till the car was warmed up say about 15mins then accelerated and the second turbo kicked in fine.

But just before i got to work there is a long straight, and I checked again, and again the second turbo felt like in hadn\'t kicked in

Any Idea\'s?

I had a look at this post could it be the same problem?
http://www.mazdarotaryclub.com/forums/showthread.php?t=24071&highlight=boost