Hi coreyva,
The curly braces prevent character interpretation. Can you try this:
Replace '".*~/' with '/'
STREAM::expression {@src="~/@src="http://devcentral.f5.com/@ @src="http://devcentral.f5.com/~/@src="http://devcentral.f5.com/@ @src="http://devcentral.f5.com/.*/~/@src="http://devcentral.f5.com/@}
If that doesn't work, can you try a simple find/replace string to make sure the response is being parsed correctly (ie, it's not compressed)? If it's compressed, you should either disable compression on the servers or remove the Accept-Encoding header from the requests in the iRule.
Also, you should move STREAM::disable to HTTP_REQUEST to prevent the stream filter from being enabled on a subsequent HTTP request.
Aaron