Zen Cart Expert Needed: fix Redirect Loop in shopping cart

Hello, I am running Zen Cart 1.3.9d, and having some problems with my shopping cart. In an attempt to fix a redirect loop error that 10% of my customers get, a previous developer accidentally broke my shopping cart. I'd like both fixed as quickly as possible. should be a very simple fix. Also, there are a couple of very minor edits (spacing on top banner, adding a paragraph of text) that also need to be done. Total time on these is less than a half hour. I'd like to have someone work with me to have all of these issues fixed by the end of the week. Good communication and timeliness are essential. Please address my specific concerns in your reply, or you will be deleted. Looking to start this morning. Thanks! Jason