HELP! Getting 500 Internal Server Error

[CouponWCents]

It turns our thread link from this:
http://couponwithcents.com/showthread.php?10875


To this:
http://couponwithcents.com/PWMSL/showthread.php?10875

Why is it making them letters appear in the link? Every time it does this, we get Internal Server Error

[LifesGreatestGift]

i would start by checking your URL rewriting rules. (.htaccess etc)

[CouponWCents]

I have no clue how to do that.

[Lynne]

What is changing your thread link and where? I was able to go to http://couponwithcents.com/showthread.php?10875 with no problems. None of the links I click on have a /PWMSL in them.

[CouponWCents]

If you keep refreshing, you will eventually get 5 letters after the www.couponwithcents.com/
It is driving members away and I don't know what to do. It is random but happens at least once every 5 refreshes.

[OldSchoolDSL]

Not affecting me and I refreshed the site 20x manually.

Than to double check the possible "random affect" you claim... I used a custom script to check re-write over 50x

Please ignore the IP 76.11x.xxx.xxx range you may have noticed.... But my point is... All seems well here.

[Lynne]

What do you see in your access_logs and error_logs? Look in your error_logs for when this occurs, then look in your access_logs for the time just before and see what is going on.