ios6.0.1 => Problem with office network desktop computers

Hi,

We have a few iPhones connected onto our office computer network via a WIFI router.

While those iPhones were running IOS 5, we had no issues.

Now, since IOS 6 - and even IOS 6.0.1 is running on those iPhones, I have 2 iPhones causing network issues to DESKTOP COMPUTERS when connected to the office network through WIFI.

Basically, when those iPhones are connected to our network via WIFI, always the same 2 desktop computers then have network connectivity issues.

Those computers have the following IP address:

Computer A: 192.168.1.92

Computer B: 192.168.1.103

When let's say iPhone A is connected to the WIFI router, then Computer A starts to have network issue - ping does not work anymore - or only randomly - user cannot printed - computer cannot connect to Windows Shares anymore.

I have found about that by changing the IP address of the computer the problem was then solved.

I have then check the IP address used by the iPhone A ... it is not the original one used by the Computer A ... It is a different IP address provided by our DHCP server ... so the problem is not there (?).

I then ran an nmap request on 192.168.1.92 while Computer A had issue ...and found on that the MAC ADDRESS reported was not the one of Computer A - but the one of iPhone A !!!

So, when iPhone A connects to the network via WIFI - it seems to confuse the switches despites not having the same IP address ...

If I ask my collegue to switch the WIFI off on his iPhone, then the problem disappear straight away ... No more issue with the computer and its IP address 192.168.1.92 ... and nmap then reports the correct computer MAC ADDRESS.

The same problem happens with Computer B and iPhone B ...

We have RESET NETWORK settings on both iPhones but this did now solved the issue.

Can someone help out ?

Thanks & regards

GL