Markets are forward looking not backwards. A share price does...

Markets are forward looking not backwards. A share price does not reflect what the company earned last year, it reflects what it will earn next year.
So whether a company beats guidance or not is immaterial - what is important is whether it can sustain the growth.

In TPG's case, they have stated that FY11 EBITDA will be the same as FY10 (add TPG + Pipe in FY10 = $216m = forecast for FY11)

TPM sits on a high P/E which indicates high growth - if there is no growth that P/E is going to have to come down.