Windows 8.1 Pro, 64-bit
Intel Core i7-2630QM @ 2.00GHz
TXS Version: TeXstudio 2.6.6 (hg 4105+:b24377c712d7+)
1. My internet connection is working fine.
2. I also encountered this in 2.6.4 before re-installing windows.
3. Last check time stamp next to "Check Now" button says "6.11.2013 18:56", even though I installed TXS yesterday, after having re-installed windows yesterday as well.
4. I have been trying unsuccessfully to build from the repository to fix the annoying home/end bug issue, and the update button should have told me that 2.6.6 was out to save me the trouble, but since it didn't work I didn't know. I only found out after going back to the site to re-install after having re-installed my OS. i.e. this should be fixed with priority since there's no point doing updates if people don't know it's there.