Fico scores are a difficult thing, and how they are affected by what balance's you have and how you manage them is as difficult to predict. 605 is not such a good rating, while there are worse scores, there are something's you could probably do to raise it.
Seeing how you've made timely payment's on your cards, contact the company's and request a credit limit increase. Should they agree to this by no mean's increase your balances. If your limit's are 1K, pay them off. Keep making your truck payment's on time, and when you do charge something on your card, pay it off in a timely manner.
Doing this for 6 month's will certainly raise your score. MyFico.com is a good site to see whats going on with your scores, the info is clear and upfront. Easy to read and understand.
I became a member of a local credit union here last year, and found them to be far easier to deal with than a bank, even my own bank. Hell they gave me a loan for a new truck, my bonnie, and transfered a balance on a high intrest auto loan.
