I'm actually having the exact same problem.
I'm on the cusp of purchasing OW, but lately I've been noticing that some pages will take a really long time to start loading and sometimes won't really load much of anything at all.
A 'fix' I've found is to click to stop loading, then start the page loading again and it will pop up nice and fast in true OW form.
If, however I take the exact URL and load it into Safari or Netnewswire, the same delay does not exist.
The most recent site this has occurred on was
www.vajacases.com. I loaded this URL into Safari and/or NNW immediately after trying to load it in OW and saw no delay at all.
I just also note that I have MenuMeters installed and while OW is delayed in it's loading, but bandwidth usage is hovering at zero the entire time.
I've also tried tweaking my Network settings using Tinkertool System to no avail. Broadband optimized and default yield the same result.
Lastly, ISP tests will give me a result of 1500Kb approx. one time when OW isn't happy and then immediately after that I will consistently get nearly 6000Kb which is right where it should be.
I hope there is a solve for this 'cause I was really excited about OW and ready to buy. My demo has only a few days left to go.