profile cash

Hello, Im encountering serious problem. I use dolphin 6.1.6 and using my compay's internet connection through proxy server. when one member logged in to the site others cannot register their profile. it says that you are already registered and displays his/her profile photo in top right corner who already logged in. this is serious problem how can i fix it? its due to cash in profiles? what should i do? Thanks in advance

Spend the cash or go in and clear your server's cache!! Couldn't resist that one.  Now, as for your problem, is this when one person is logged in noone else can register regardless of where they are or that when someone at your company logs into the site that noone else with a terminal on your company's internet connection can registe?  If it is the latter, then I'd say the issue is coming up that YOUR server is reading the router's IP signature and not dropping the cookies all the way to the end terminals browser.  By this I mean, on my sites I can open up 4 different browsers on my laptop and log into my site as 4 different users (1 user per browser type) and it will keep the sorted as the cookies are being dropped and read at the browser.  Your server appears to be dropping and reading them at the router or at your company's server. 

my company members cannot register if one of my company memebr logged in. but gmail yahoo other accounts is ok. why this issue is only for dolphin

 It was explained to you above your last post.  You have all the terminals at your company reflecting the same IP, more than likely your company server is being used to route all Internet connections and is literally making the site server think every terminal is the same.

The only other situation/solution I can see is that somehow you have caused it to start denying e-mails that end with @yourcompany.com and thus it's erring out.  Never before seen this problem before with Dolphin.