Don't use any of these characters: * ? < > | " : \ / (asterisk, question mark, left and right-angle bracket, pipe, straight quotation marks, colon, BACKSLASH, FORWARD SLASH). Also, don't add the .qdf extension; Quicken does that for you.
After adding accounts, see if you are experiencing the same problems in this test file.
Flipr said: Created new test account, added only CapitalOne accounts, all 3 capitalone accounts successfully imported, pulling 86 days of previous transactions, including new transactions from today.
Flipr said: c:\users\flipr\documents
Flipr said: Weird, did the above, first connection after logging back in gave me cc506 error on 3 accounts. Went thru the fix, re-authorized thru CapOne, got transactions downloaded. Will try for a couple days to see if issue returns.