Q: One of my podcast episodes won't show up on itunes!

When you have 'Smartcast' enabled in Feedburner you can write various tags such as 'itunes:subtitle' etc. and it over-writes those in the original feed (if they are there).

AFAIK you can't edit the actual code. If there isn't a place provided to enter the file size then I don't see that you can do anything about it. Of course if you constructed your feed in something other than Tumblr, choosing something which constructs podcast feeds properly, then that would presumably solve it as the tags would feed through to Feedburner.

However it occurs to me that we've wandered off the original complaint, the missing episode 6. Apple have drawn attention to the 'length' attribute but I'm beginning to think this is a red herring. Feedvalidator would flag it as an error, but I suspect that in fact it's not really an issue and Apple are just presenting you with an excuse. After all your other episode have the same error and they appear OK.

I think the problem lies with the Store and there's nothing you can do about it. You should correct what issues you can on general principles, but after all this I should ignore the 'length' issue.

If it is, as it appears to be, a problem in the Store there isn't really anything you can do about it - other people are complaining of similar problems.

As regards missing episodes, Support have confirmed that there is an ongoing problem. They say that sufferers should contact them and request a reindex; that should solve it for that particular episode. Go to https://itunespartner.apple.com/en/podcasts/overview and click the 'Contact Us' link at the bottom of the page.