HP 1910-8G, NFS/CIFS between VLAN

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Good day.

I have some problem with HP 1910-8G Switch JG348A

Software Version 
5.20 Release 1513P66 

Hardware Version 
REV.A 

Bootrom Version 
167

Settings:

1-4ports - VLAN 1

5-8ports - VLAN 99

ip address:

VLAN1 - 192.168.7.238/24

VLAN99 - 192.168.99.1/24

I connected computer1 to port 1 with such settings:

192.168.99.2/24 

GW - 192.168.99.1

And computer2 to port 5:

192.168.7.99/24

GW - 192.168.7.238

The "pings" work good in both direction from computer1 to computer2 and the other way as well.

From the computer1 I can open webpage from the local web-server (192.168.7.99). 

But i can't open sharing resources - when i try to open it I've received this error - "\\192.168.7.99.The Network Path Cannot Be Found"

If both computers are in the same network - 192.168.7.0/24 it's working without any problems. 

It's a similar problem here - 

http://h30499.www3.hp.com/t5/Web-and-Unmanaged/HP-Procurve-1810G-24-quot-Auto-DoS-quot-prevents-NIS-and-NFS/td-p/4693460#.Uvmb5WJ_upA 

But i can't find any setting in web-management about DOS-prevention in my HP-1910-8G, although in the description of this switch there is such feature - "automatic denial-of-service prevention". 

Thanks in advance for any help.