That's your problem then, no need to get a newer version (it is the new version), just follow these instructions:
From their site below the download:
WARNING: GUI Miner's official release has still not updated BTC Guild's server listing. If you downloaded it elsewhere, use 'Other' with Host stratum.btcguild.com and port 3333, or eu-stratum.btcguild.com for EU. Failure to do this will put you on the getwork protocol which is not recommended.
K.
Err, unless I'm reading that wrong, that warning is just for if you've downloaded guiminer from another source. It doesn't say anything about the version you get directly from them. Regardless, I actually tried both their version and the official version when I read that on the BTC guild site. It still didn't work unfortunately.