As I mentioned before, your site seems responsive to me at the moment. Mor einfo is needed about when it gets slow and what else is going on on the server. In shared hosting its possible other sites on the server are getting heavy traffic at times and this can impact your site.
Other things that can cause slowness.
1. database is overly busy - also subject to traffic from other sites/applications
2. database on a different machine and DNS server is too busy causing slow dns resolution to connect to the db server
3. Something running on the same server has a memory leak and it depletes available resources at times
There is know way for me to know which if any of these are causes in your installation. All I can say is mojoportal runs very fast for sites I'm working with.
Again, I think keeping a close eye on the mojoportal error log and analysis of the IIS web logs is what I would do to troubleshoot the problem.
At the moment I'm not seeing the symptom.
Hope it helps,
Joe