I have an JavaScript API application based on the "Create WebMap from ID" sample. One of the webmap layers points to a web-accessible csv file; the request for said file when the app loads requires a proxy page. However, the app seems to emit the following request, which you can see produces "proxy.ashx?" twice:
This a bug that only happens when using a webmap with a CSV layer and specifying the URL for your proxy without a domain. We found this a few weeks back and there is a fix in the next release of the API (due out around dev summit time).
It looks like you might have already found this as you have the full URL to your proxy commented out:
var proxyUrl = "proxy.ashx"; // "http://apps.esri.ca/proxy/proxy.ashx";//
Does your app work if you specify the full URL to the proxy? I know this makes your app a bit more brittle (one more thing to change when moving dev to staging to prod) but it's the easiest way to make this work at 2.7.