I don't think it's that, actually. IMHO, the problem is that which gfunk suggested: Fighter is just fine for a few levels, but is far better for dipping. Ftr4/Rgr6/PrC10 makes a better archer than a straight fighter, Ftr4/Bbn16 (or Ftr4/Bbn6/FB, but that's just dangerous) makes a much more effective melee combatant, and Ftr4/Pal1/Clr15 is a better all-round character. The thing that is needed to fix this, IMHO, is a real set of class abilities (not just feats), more and better high-level feats, or a combination of same. IMC, I give fighters a medium Will save (which they desperately need, having only one good save and, unlike other one-save classes, no means to boost save effectiveness through divine grace, rage, evasion, slippery mind, etc.) and allow them (only) to choose from a much more powerful selection of feats from 10th level onward, including Armor Skin, Improved WWA, Overwhelming Critical, and a few others from the ELH (though not the heavy hitters like Damage Reduction and Fast Healing). I also give them Profession as a class skill.