Landing problem

A few times whilst landing the B737 (ILS) the plane turns to rwy heading and then the AP turns off the ALT Hold then instead of the plane making its decent down toward the runway the nose lift to a near stall and it starts climbing up at a very fast rate beyond FL10 and makes no attempt to descend.

I have landed the 737 hundreds of times on FSX and it has only done it about 5 time.

Is this my fault or a FSX issue, I'm 99% sure all settings are correct my end.

Thanks

I have seen the autopilot trying to intercept the glidescope by climbing. Although that was only when I was making a mess of the approach.

Maybe related:
I have seen the alt and or asc/desc rate dials getting kinda stuck. It just doesn't follow what has been set. Increasing and then decreasing the ascent/descent rate by one get's it unstuck. I have seen the same thing in FS9.

I believe you are hitting the APP hold button too soon.