The 'current' SDK determines what is in any new *.bin files you generate.
When you switch back to an old version of cgminer you are using the old *.bin generated with an old SDK unless you delete them.
I think kano is right. At least it was the reason preventing me from updating from version 2.1.2 since phatk opencl code has changed and cgminer had to recompile (or whatever it does with .bin files) it.When you switch back to an old version of cgminer you are using the old *.bin generated with an old SDK unless you delete them.
I had trouble deleting APP SDK runtimes. Somehow it stayed in the system after uninstall.
Here's what you need to do:
1) Uninstall either APP SDK runtimes or whole Catalyst suite through AMD uninstall utility.
2) Search for amdocl.dll and OpenCL.dll in Windows directory and delete them
3) In case you uninstalled whole suite, reinstall it with custom install and uncheck APP SDK runtimes
4) Download and install needed OpenCL driver. Older version avalable for direct download here:
http://support.amd.com/us/gpudownload/windows/previous/Pages/radeonaiw_vista64.aspx
http://support.amd.com/us/gpudownload/windows/previous/Pages/radeonaiw_vista32.aspx
http://support.amd.com/us/gpudownload/windows/previous/Pages/radeonaiw_xp.aspx
For newer versions - download suite, install and select only AMD APP runtimes. You can backup OpenCL.msi from AMD/ATI temp directory on C: for future use.
You can choose driver version according to needed SDK version:
http://developer.amd.com/sdks/AMDAPPSDK/downloads/pages/AMDAPPSDKDownloadArchive.aspx