Funny, I've heard of this issue a lot with Firefox, but not with Chrome.
Anyway, try these in this order:
1. Delete any bookmarks in Chrome to the site.
2. Clear your browsing and download history.
3. Restart Chrome.
4. Visited the site and bookmarked it again.
Another solution I just found involved deleting the file that stores those icons for Chrome, forcing Chrome to create it again with updated icons, but this will delete ALL favicons, not just your site's.
Anyway, hope that helps out a bit, Mulreay. Let us know how you get on.
EDIT
I assume this site you're referring to is that Space and Science site in your signature (which I'm looking forward to digging through eventually). I'm attaching the favicon as I see it now.
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