Blank page randomly but frequently

Running Drupal 5.1, my site is normally stable.

But often, when visiting a page (a view-generated page, if that matters), it will show fine the FIRST time. But navigating away, then back, or hitting exactly the same URL again, the revisited page will often be blank. There's no visible error, just a totally blank browser screen.

Opening exactly the same URL on another computer, the page is viewable. Navigating on that computer might work fine, or it might end up displaying the blank page again.

This happens in Firefox 2 and IE 7, on a variety of WinXP and WinVista PCs.

Clearing the browser's cache and/or restarting the PC sometimes "fixes" the blank page, but not reliably, so I'm not sure it's a client-side issue. Restarting Apache doesn't help.

One test site where it keeps happening is http://rv.advisor.com. I just went there as an anonymous user. Saw the main page. Then went into the one displayed story. Then clicked Home -- blank page. But if I go to the actual path of the main page (which uses a view), it displays: http://rv.advisor.com/v/rv. But if I then click the breadcrumb Home or the site name or retype the site URL, the page -- the same page, supposedly -- is again blank.

I think the path to the main page is properly specified in the site's settings.php (otherwise the page wouldn't display on first visit). Here's how it is specified:

$base_url = 'http://rv.advisor.com';  

and...

 $conf = array(
  'site_name' => 'RV Advisor',
  'site_slogan' => 'The Advisor Guide to RV Travel & Mobile Living',
  'theme_default' => 'adv-bluemarine',
  'anonymous' => 'Visitor',
  'site_frontpage' => 'v/rv',
 );

I don't suspect this code because I use the same with other sites without problem. And on this site, it works often, just not all the time.

My sense is it works more reliably with an authenticated user, especially an administrator, even though all appropriate access rights are correct for authenticated and anonymous users -- anyone should be able to read any published content. And, since it works some of the time, it's not likely to be access control, unless it is flakey.

Is there a known problem with view-generated pages? The view is simple. It selects pages with a specific taxonomy value ("RV Travel"), then applies the distinct filter to eliminate any duplicates.

Besides, the view doesn't generate the entire page, it generates the content section. What would cause an entire page to be blank, and/or, the browser to think it has retrieved the page (hence, no error message) when it hasn't? The blank page has NO information, not even HTTP headers.

I realize this isn't much to go on, but it seems to be Drupal alone. I'm running a variety of PHP-based apps on the same LAMP server (WikiMedia, Gallery 2, etc) and NEVER have a problem like this. But I've had a blank page problem randomly with every version of Drupal I've used since 4.5, and I'm really bummed it's happening in 5.1.

Thoughts?