you didnt set those permissions to 777 and 666? if you didnt then you have bigger issues that i would know what to do with. those files by default are set at 755 and 644, i have installed this script a few hundred times and have never encountered what you are describing, not to say it hasnt happened, but i have not seen it, and i have installed aon most every platform and setup imaginable.

also, it appears to me that you are missing several files. i forget the last count that i done, but i thought see more it was somewhere around 80 files that need to be chmod'ed.

how did you upload the files? do you have all your folders in place? need to take a look at what is in the zip file of dolphin, compared to what is actually on the server, but from what you have a screenshot of, i would say you are missing a few directories, and possibly files.

Resolving 502 errors - general

This problem is due to poor IP communication between back-end computers, possibly including the Web server at the site you are trying to visit. Before analysing this problem, you should clear your browser cache completely.

If you are surfing the Web and see this problem for all Web sites you try to visit, then either 1) your ISP has a major equipment failure/overload or 2) there is something wrong with your internal Internet connection e.g. your firewall is not functioning correctly. In the first case, only your ISP can help you. In the second case, you need to fix whatever it is that is preventing you reaching the Internet.

If you get this problem for only some of the Web sites you try to visit then it is likely to be a problem at those sites i.e. one of their pieces of equipment is failing/overloaded. Contact the people at those sites.

Resolving 502 errors - CheckUpDown

Use of proxies and caching is increasing on the Web. Our CheckUpDown robot will always try to 'drill through' to the real computer that actually hosts your Web site, but we do not have complete control over where our HTTP request actually ends up. If only one link in the chain of computers dealing with our HTTP request is broken, then an error such as 502 can easily occur.

resource on that info is from the following
http://www.checkupdown.com/status/E502.html

good luck,
DosDawg