ITunes is truncating enclosure URLs to 511 characters, but only inside the 'iTunes Store' panel

Question

URLs for my audio and video files are usually about 600 characters long. Inside the <enclosure> of my podcast feeds, I use a shorter URL that redirects (HTTP 302) to the longer URL.
This normally works fine. I can add an RSS feed in Advanced > Subscribe to Podcast, and it works fine. I can find the podcast inside the iTunes store and subscribe to it, and that works fine also. iTunes manages the podcasts as expected, downloads new episodes, and plays them back without a problem.
What doesn't work is when I find the podcast inside the iTunes store and try to play the episodes right there instead of subscribing. On that page (you know the one, it shows the podcast title and info and lists the latest ten episodes) when I try to preview any episode by clicking the play button on that episode, it fails to play. This feature works for most podcasts, but not for the ones I'm publishing.
I've inspected my network traffic and found that iTunes is going to the shorter url and following the redirect as expected, but when it sends the second GET request, it only uses the first 511 bytes of the longer URL. I can only assume that this is because somewhere in the iTunes codebase, it's storing this URL value in a C string inside a 512 byte buffer and truncating anything that doesn't fit.
I'm using iTunes 10.5 on OSX 10.6
Has anybody seen this before? Is there a workaround? Is there a version of iTunes that this doesn't happen in? Is it a known bug?

Answer 1

600 characters! I don't think I've ever seen an URL that long - though a bit of quick research shows that this question has been asked about browsers and apparently the maximum limit for IE7 was 2048 characters, though somebody testing this with IE8 found it could handle 4095 characters.
As to the iTunes Store, no-one in these forums would have any way of knowing whether there is an imposed limit in iTunes - only the programmers would know, and you know how secretive Apple is. If you are finding that long URLs fall over, then obviously you've hit a brick wall with it, and I don't see any change of it changing. I imagine you've already considered using a shorter URL, and are using a longer one for a reason, but in the end I doubt you have any option but to change your practice, as I would think the chance of Apple changing theirs is approaching nil.