I recently performed an update from 184.108.40.206 to 220.127.116.11 and I noticed that the behavior of GetRemoteFileTextData changed. In the former version, the method returned right away with an empty string (or null I can't remember off the top of my head) if the file doesn't exist. The latter version waits for the timeout duration before returning. This is easily worked around by testing that the file exists with GetSizeByName().
I looked through the release notes and did see documentation of this api behavior change and it worries me that something else could exist that I haven't caught in my testing. Do you keep a record of API changes with each major release?