bread sticky after baking I hope someone has an answer.

Although I have been baking 2 or 3 loaves a week for 4 years using a breadmaker, and I haven't recently changed my flour mix or any ingredient proportions, my last 3 loaves have risen fully as normal, but, when cutting a slice, the bread is sticky and heavy and goes to paste when chewing it.

The bread has also become friable, the gluten structure seems to have gone, i can pull the slice apart easily, it has no structure holding it together. The air bubble distibution in the loaf is good and even as normal, no large air pockets.

I tried reducing the usual amount of water, no difference. The yeast is new, the flours are new. If it makes an difference, this has happened after the recent hot weather although my ingredients are stored away from warm or humid air.

Any ideas, I am wary of baking another now, and we need some bread cooked !!

Regards Jonathan
It sounds like the breadmaker is not cooking properly.  If the bread dough feels correct but is the baked loaf is fragile and sticky inside, it is under-cooked.  This could be a result of problems with a thermostat, heating element, or possibly the timer.

To solve this problem, try taking the bread maker out of equation by baking in an oven.  Use an inverted, oiled sheet pan, and hand-shape the dough (The Fresh Loaf has instructions), or use an appropriately-sized loaf pan.  Check the bread 5 minutes before it should be cooked (to make sure it doesn't over-bake due to using oven instead of bread-maker), and keep checking it every 5 or so minutes until done.  

If this solves the problem, use the breadmaker for mixing and not baking... or replace/repair it.