Problem with FTP path given by DHCP for auto-configuration

Hi, 

I use a FTP server (W2K8R2) to auto-configure all my Wyse Thin clients. 
For the moment I have 5 remote sites (or clients) that use this server and I never get a problem. Every site have a dedicated folder on the FTP server. 

On remote sites, DHCP settings are given by a Cisco 881 router. 

For one remote site I have a problem with the FTP path given by the DHCP, the path was "changed" with false value. 

DHCP Config: 

Client 1: 

ip dhcp pool LAN 
network 10.0.243.192 255.255.255.192 
default-router 10.0.243.193 
dns-server 10.0.7.2 10.0.7.20 
option 161 ip 192.168.100.4 
option 162 ascii "/lanty$" 

Result on the thin client interface in File Servers/Path (same in the FTP logs) 
192.168.100.4/client1 -> Work fine 


Client 2: 

ip dhcp pool Data 
network 10.0.192.0 255.255.255.0 
default-router 10.0.192.1 
dns-server 192.168.1.7 192.168.1.32 
option 161 ip 192.168.100.4 
option 162 ascii "/agir$" 

Result on the thin client interface in File Servers/Path (same in the FTP logs) 
192.168.100.4/"/client2$"/wyse -> Doesn't work 

We have try many settings on the Cisco DHCP router and never found why the path is incorrectly set from DHCP. 

Have someone encounter this problem??? 

FTP server is not the problem, we disable the option 161/162 settings and set it manually to the Wyse and configuration was download without problem... 

Thanks for your help