The Spiked chain is supposed to be weapon finesseable under 3.5 rules. I built everything around a guy before finding this out. Boo.
i could fix this. But I'm not gonna. It's my effort to help promote other people getting off their can and contributing too. However i will tell you all that itt should be as simple as changing the properties of all spiked chains in the protos.
I have not been able to reproduce your problem. Started out a new character. Human fighter 18 dex, Spiked chain prof and focus as well as weapon finesse. To hit bonus of +6 just as it should be. Have you installed the patch? If so you will have to start over in order to be sure that the rulefixes work as intended. If you don't want to start over you simply burned a feat on finesse but the character can still be salvaged. Use Bull's Strength spell together with Gloves of Giant Strength +6. This will net you +5 to hit and damage rather than just +4 to to hit if you had been using the Finesse feat.