And Welcome
Your mx Google sitemap installation works nicely.
Talking of what could be done to go further into search engine optimizing your forum, I think you should think about implementing at least the
phpBB SEO simple mod rewrite.
It will make your forum's URLs a lot more attractive to bots.
Now, if you plan to often mix Latin characters in your forums and topic titles it could be interesting to see if the UTF-8 advanced version I build up for non Latin characters would not be a better solution.
You're not using UTF-8, (I see charset=gb2312), but the method should work the same.
What this one does is only inject the latin characters strings from the titles, and fells down to a static rewrite for title not containing any latin characters.
For example : xxxxxCLIxxAsteriskxxxxx
would be injected as cli-asterisk-vtxx.html
but XXXXXX would give topic-vtxx.html
Note that I replace the characters I could not write down in my available char-sets with "xx".
This non latin char-set version of the advanced mod rewrite is not released yet, but up and running on live site, so I can post you the code changes if you're interested. It's more code changes than the simple one, but can be interesting.
You can as well think about the mixed mod rewrite, easier to deal with as only forums will have titles injected in their URLs, the choice depends on how much will you use Latin characters in your titles.
If you decide to use mod rewritten URLs on your forum, do not submit your Google sitemap (or un-submit it now), we'll take car of it when URLs will be final.
And

, after I previewed this post, I saw your answer to your self appear in the review frame.
So yes it's normal to see SIDs after log-in, and in acp by the way. Don't worry bots do not log-in and do not visit phpBB's ACP
And 1and1 is ready for mod_rewrite
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