Sometimes you just can't get the shipping to charge correctly.

First check the tare wt in Configuration >> Shipping and Packaging, if it is set to 3, all wts will be 3kg/lbs/gms out.

Then is the wt actually in the range you have specified? In these examples I am assuming everything is in kg.

25:8.50
This means anything upto 25 kg is £8.50 and anything above this method is not available.

25:8.50,10000:0.00
This one gives free shipping over 25 kg but this method is not available over 10,000kg.

9999999:0.00
This one gives free shipping up to 9,999,999k which will probably deal with most orders.

Finally check if the delivery address of the order is actually in the shipping zone used by the table rate.

If the Shipping Zone is blank it applies worldwide.

There, now you should have this working.