Hi,
I'm not sure if its a wordpress thing or a MediaTemple issue.
I was running WordPress 2.0.6 on Dreamhost. I installed WP2.1 on MediaTemple and moved my database there.
Now, whenever I try create a new post (or edit an existing post) and try to save it, it *very frequently* gives me the error:
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Bad Request
Your browser sent a request that this server could not understand.
Apache/2.0.54 Server at gridserver.com Port 80
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I upgraded WP on Dreamhost and it hasn't given me this error. But then I haven't rigorously tested it.