I have had connection issues with RV042, RV082, and now RV180. I think I finally found the cause to be a feature used on Windows 2008 R2 and newer that provide DNS services.
The symptoms are: intermittent problems loading web pages, slow loading pages
The cause in our case was a feature of Windows DNS server that potentially conflicts with some firewalls. This Microsoft knowledgebase article describes the issue and the fix:
Some DNS name queries are unsuccessful after you deploy a Windows-based DNS server
http://support.microsoft.com/kb/832223
I hope this helps others that have been pulling their hair out looking for a solution. And hopefully we might see future firmware updates that fix this issue on cisco's routers or provide a way to make adjustments as discussed in this support article.
