CS5.5 installation problems

For some unknown reason my CS5.5 Standard Suite stopped working yesterday, right after I had had an issue with my monitor, which I solved by switching to a different monitor. When I went to open the applications it wanted my serial number which I couldn't find at the time. I tried to uninstall the applications and reinstall from my time machine backup. Then I found my serial number but it still wouldn't work. I chatted with customer service and was instructed to redownload CS5.5 from Adobe and reinstall. I did that, and now when I try to launch the programs, it is an endless loop of the licensing agreement, then asking me for the serial number, then it just cycles back to the licensing agreement, and so on. When I type in the serial number, I get a green check mark and it seems to be correct, but I can't get past that repeating loop.

The exact suite I originally had was Creative Suite 5.5 Design Standard Student and Teacher Edition (Mac - Download). I thought maybe the issue was it was a different version of the suite, but since it gives me a green check mark when I type in my serial number, and the customer service rep seemed to think the serial number would work with a new download of CS5.5, I thought it should work.

I chatted with another person at customer service who said they were unable to help me and I needed to visit the forum, so I am really hoping someone will be able to help please! Thank you!