I finally fixed this.
I had a sneaking suspicion that something with Office 2010 was conflicting with Access 2007 since I checked my coworker's computer (Office 2013) and the export to Excel was functioning properly. Besides the export to Excel issue, I also started getting other weird errors that seemed related to Office 2010 (long story short: office was trying to "install" Access every time I opened a .accdb file from explorer but it wasn't working because we don't have Access included in our Office Suite).
In any case, to solve this I uninstalled Office 2010 and installed 2013. Now everything is working properly.
Thank you again for all your help!