Ask HN: Do I hate web development or do I just need a switch-up?

I'm trying to decide whether I can do this forever and I need to know a couple things: whether my situation is industry-typical and if so, will I eventually get used to it. First, a little background: I've loved computers ever since I was a kid. I've always loved learning new stuff and I've made some pretty cool side projects. Somehow, I never even considered the job aspect of it until a couple years ago. I guess I was too busy enjoying it to realize it was a viable career. Anyway.

I've been working at a web agency for almost a year now, I'm in some gray area between intern and developer (in that I get paid as an intern but work on full projects without supervision like a developer), and I'm starting to learn that the challenging parts of it aren't what I thought they'd be. Having some difficult task that requires learning a new way to do things isn't a problem -- it's why I fell in love with computers in the first place. I've learned in the past few months that the hardest part is sitting for hours and grinding away at someone else's kludges of spaghetti code.

We're primarily a PHP shop, and we mostly do business websites with typical content using our proprietary CMS. That's not incredibly exciting, but it's at least not terrible. Occasionally they have an interesting requirement, API hookup, etc. Sometimes I make WP themes (for SEO purposes :() or make a Drupal module, and that's also not bad. I enjoy starting a project and building it through 'til the end. Where it gets painful is when we inherit clients that have an already existing site made by their DBA that didn't know what he was doing, or worse yet, our sales team scores a client that has an ASP site ("We're technology neutral" i.e. we'll take anything) and it gets dropped in my lap even though I don't know a damn thing about ASP and don't even have a Windows install around to work on, so I'm live-editing the site using Transmit and TextMate. Oh sure, I speak 'coder-speak' so the language doesn't matter, except that the guy that made it obviously didn't speak coder-speak and has an almost incomprehensible abomination that works, but, oh my god I don't know how and I don't want to know.

Oh, or my favorite: the guy that already spent his $500 on iLance (http://www.ilance.com/) and then realized he couldn't make it do what he wants so he hires us and we have to use iLance because he already bought it, damn it! while iLance is probably the most incompetent chunk of PHP I've ever looked at. Seriously, like "I don't know how to use arguments to make this expression, so I'll just concatenate a string of PHP code from the post variables you sent me and ram it through eval()"-bad.

tl;dr I find it miserable to work on someone else's sloppy code. It feels like I'm doing a job no more skilled than sweeping the floors at a supermarket or something. Just pounding away at a keyboard for 9 hours and then going home feeling like my brain is fried. Does it get better? Does my situation (with dramatic, frustrated emphases accounted for) seem typical, or is the place I work just particularly messy sounding? Any advice?