I don't know if I am a bad programmer because I often make mistakes when outputting information on a site, things like "thanx for subscribing to our service" instead of "Thanks for subscribing to our service".
I think this is because I usually don't concentrate on the spelling, my main focus is to get the functionality running perfectly. Please give me your opinion, do you concentrate on the spellings or the functionality?
IMO attention must be paid to both. Cool logic and reliability are no excuse for crappy texts.
You could separate checking the resource from changing the source. When you do changes first change the code, test everything, then proofread the resources.
If I'm writing a message which will be visible to users, I'll make sure it's clear and correct. If I'm writing a message which will only be visible to other developers, I'm slightly less careful - in particular, typos aren't really a problem, so long as I express myself clearly.
Fortunately my spelling/typing/grammar is reasonably good anyway, so I don't need to think too hard about this, but I think it is important for customer-facing text.
Developers often aren't very good at writing messages for users. It can be hard to put yourself in the position of someone who really has no idea about what's going on in the background: they just want to get their email (or whatever it is) working. If you're lucky, you may be able to get a technical writer to help compose appropriate text.
The CTO at my last job was dyslexic, and a completely brilliant programmer and manager. Every now and then I would go and make a spelling correction to one of his method or variable names (C# handles the refactoring pretty well) and it didn't really matter that much.
When there's user interface work it's much more important to spell things correctly coz it looks very shabby to have a misspelled UI.