I am having intermittant sales go through your Gateway.  I have seen at least 4 transactions processed and several denied.  I have not changed anything in my web design in three years in conjunction with authorize.net.  I believe I may be having a tim eout issue.  I also use the SIM integration.  I did notice that the version in my account was set to 3.0 and my SIM transaction was set to 3.1.  The customer care associate assisted me in changing this to 3.1, but it did not reolves the issue I am having below:

The remote name could not be resolved: 'secure.authorize.net'

it errors on my code here:

Line 87:         myrequest = System.Net.HttpWebRequest.Create("https://secure.authorize.net/gateway/transact.dll?" & strLoginTest & vPostData)

Line 88: thresponse = myrequest.GetResponse - ERRORS here.

Server Error in '/' Application.

The remote name could not be resolved: 'secure.authorize.net'

I called into customer care and they stated with intermittent sales being processed they cannot assist me and my only recourse is to see if anyone else has encounter this issue.  Any help woul be great