Strange visit in visitor log

I have the version 1.82 of piwik and I have tried to import Log of urchin.
The log import fine, but the result of piwik and urchin are not the same (number of visit, time per pages …).

I have checked the Visitor Log, and some visitors have many action in 0s (for example 17 action in 0s).
If I check, the details of the visit, I have a long time between some page visited. For example:
I have Two pages visited the 08 May 2012 at 20:35 and 15 pages visited the 15 May between 17:40 17:45.
Why this pages are grouped in the same visit ?
I have try change the visit_standard_length parameter, but I have the same error.
The website have the same problem:
Dim 24 Jun - 21:55:21
FAI: Inconnu
6 Actions - 0s

  1. 301 Moved Permanently Dim 24 Jun 18:23:44
  2. 301 Moved Permanently Dim 24 Jun 20:21:44
  3. 301 Moved Permanently Dim 24 Jun 20:49:48
  4. 301 Moved Permanently Dim 24 Jun 21:10:19
  5. 301 Moved Permanently Dim 24 Jun 21:10:19
  6. 301 Moved Permanently Dim 24 Jun 21:55:21

Have you a solution for this problem ?
Best regards

Can you please show a screenshot of the bug? Thanks

A screen shot of the web site

The first link in visit:
[attachment 707 piwik_website1.jpg]

The second link :
[attachment 708 piwik_website2.jpg]

They have 5 Hours and 8 min between the 2 links.

A screenshot of my website.
the first link :
[attachment 709 weblink1.jpg]

The last link:
[attachment 710 weblink2.jpg]

Thanks for the report. I looked at the code but cannot understand how this bug can happen.

what would be very useful would be to have a log file that I can reproduce the issue. Could you manage to reproduce the issue with a small log file ? Thanks