vuser_init.c(14): Registering web_reg_find was successful
vuser_init.c(17): web_set_max_html_param_len was successful
vuser_init.c(23): Registering web_reg_save_param was successful
vuser_init.c(30): Error -27796: Failed to connect to server "ipaddress":  Connection timed out
End auto log messages stack.
Start auto log messages stack.
vuser_init.c(30): Warning -26000: Empty or no response for URL="
vuser_init.c(30): Error -26366: "Text=
Subscriber Log On
" not found for web_reg_find
vuser_init.c(30): Error -26377: No match found for the requested parameter "AR_ViewState2". Check whether the requested boundaries exist in the response data. Also, if the data you want to save exceeds 1024 bytes, use web_set_max_html_param_len to increase the parameter size
vuser_init.c(30): Error -26374: The above "not found" error(s) may be explained by header and body byte counts being 0 and 0, respectively.
"I tried to change the ramp up time another tweaks but nothing seems to work."
I don't think you should be arbitrarily choosing ramp up times in an effort to lower failures...the point of your test is not to runaway from problems but uncover them and investigate.
You should determine what the expected user login rate will be in real life and then simulate that in your test. And then if the failures still occur then the application likely has a performance issue. I say likely because there's always a chance that something is not configured right in your test. So you have to be careful everything is in place and configured correctly to simulate a real life situation.
Proxy configuration as suggested by other members and did you check with the Dev team about the maximum number of connections that can be established at a given time? Some times for secure sites there is limit on number of login sessions that can be opened.