Visitor routed to homepage instead of profile

Ever so often, I'll have a profile that gets a 'broken' link and now it's happening to all new registrations.

I can look through the profiles table and compare a working profile to a broken one. All settings appear identical except of course the mandatory to be unique fields. 

But click on a hot profilelink on any page and it appears to try to load the profile but then something is not right and I suppose all the browser knows to do is go to the root.

Do any of you know what would cause this type of behavior?  Before I start trying to trace what happens when a profile link is clicked, I thought maybe someone could save me time with a suggestion or two.

What I've tried so far:

• Dumped the cache both through the admin panel and literally at a folder level.
• Killed all cookies and restarted IE, FF and Chrome but the issue is persistent.
• Looked through tables that seemed like they could be causing a problem but I'm not seeing anything unusual.
• Dumped the sys session table.
• I've pulled all the blocks off of all the profile tables so the profiles that do work show nothing but the header and footer sections. But at least you don't get routed to the homepage.

I wonder what other tables are referenced when you click on a profile link?  Strange. Very strange.

I did a rollback to a backup copy I happened to make about a week ago and it's doing it there too.  This site is not a public one so it's not like I'm getting complaints from users. I am the users. lol.  But I do want to understand what I may have done or if this is something that has happened to you before. And if so, did you track it down?

Thanks in advance.

did you check your .htaccess file? Have you modified it in any way? When removing all blocks from Profile page, do the not working profiles still redirect?

Damnit.  I guess I hit the freak'n "Report" button. I thought I was hitting Reply. Sheesh.

Anyway, apologies for that.

Actually I have hacked this thing up quite a bit to be honest. Having said that, I've kept it humming along.

I did mess with the .htaccess file but not since this issue has popped up so I don't think it's that. Plus, some of the profiles work while other do not. 

And yes, removing all the blocks from the profile page, profile edit and profile info didn't make a difference.

I'm looking through timestamps right now to see if maybe something is amiss.

Well, at the moment I'm looking at the profiles.inc file. 

I'll report back if I track something down.

Update:  Ok, I put a test db write statement in the baseprofileview.php file to see if that file is even getting called.

Interestingly enough, the 'working' profile does trigger the insert statement and writes test data to the table. But...

Trying to view the 'broken' profile does not trigger the insert statement which means I have to keep backtracking to see what calls the baseprofileview file.  Anyone know by any chance?

I found it.  ProfessorSr is the only person I have ever 'blocked' and twice now by accident - I honestly thought I clicked the Reply button but the "Reported" screen popped up - again apologies.  Twice now he's given sound advice.

What he suggested for this was to look at my .htacess file.  That's what it was. Very subtle but all fixed now.

Oh well, it was a good learning exercise to track through how the profile links work.

Thank you again ProfessorSr. And once again, I apologize for the Report error.  Sheesh.