We've got a website which has been running for a few years now. One of our customers has just started having an intermittent problem. Looking at our iis6.0 logs the service works correctly when they have a user agent beginning "mozilla/4.0+" but fails when the user agent begins "mozilla/5.0+". The particular customer only started having this problem on Wednesday.

Does anyone know the browser/upgrade which changes the 4.0 to 5.0?

The actual problem caused is that an "&" in a url parameter list is being encoded as "&". Anyone seen anything similar?

We have other users sending from browsers with the 5.0+ user agent without trouble.

Sorry about the tags but don't have the rep to create new ones.

Thanks in advance, Patrick

Edit: hi Viper_sb,

It is most probably a custom script (I'm primarily a c++ developer so don't really understand). Our site services requests from other customer developed sites, this one was done in Java script as far as I know.

we're actually getting a variety of user agents (presumably depending on which of our customers customers is accessing the service), here's a few: Mozilla/5.0+(Windows;+U;+Windows+NT+6.1;+fr;+rv:1.9.1.11)+Gecko/20100701+Firefox/3.5.11

Mozilla/5.0+(Windows;+U;+Windows+NT+5.1;+en-US)+AppleWebKit/533.4+(KHTML,+like+Gecko)+Chrome/5.0.375.126+Safari/533.4 302 0 0
Mozilla/5.0+(Macintosh;+U;+PPC+Mac+OS+X;+fr)+AppleWebKit/523.12+(KHTML,+like+Gecko)+Version/3.0.4+Safari/523.12
Mozilla/5.0+(Windows;+U;+Windows+NT+5.1;+en-US;+rv:1.9.2.8)+Gecko/20100722+Firefox/3.6.8
Mozilla/5.0+(Windows;+U;+Windows+NT+5.1;+fr;+rv:1.9.2.8)+Gecko/20100722+Firefox/3.6.8+(.NET+CLR+3.5.30729)