I have two blogs, one running wordpress 2.5.1 and one with wordpress 2.6. I was able to access Blog 1 (2.5.1) but not Blog 2 (2.6). For Blog 2, I keep getting a communications error.
Operation could not be completed NSXMLParserErrorDomain error 9
I do have the mobile applications part checked on the Settings -> Write page. Because it works on the 2.5.1 blog and not the 2.6, I can't help but think it has to do with the 2.6 blog setup. Last night, I redownloaded the wordpress install files and deleted the originals and uploaded the new files.
Still no success.