IP Management Problem

[pdu57655]

Hi,

I have 2 procurve 2910al connected with a copper cable.
I create multiple vlans onn tehem and it working fine.
I have an issue with the management of one of them.

I put an IP adress in a vlan(tag 4060) and assigned an ip adress in the first one.

The same in the second one.

Both have the same default route 0.0.0.0 0.0.0.0 192.168.1.254

My problem is :

Every 20 mins, i loose the connectivity of the first one for 20 mins.

Impossible to ping it, or telnet it also.
If i connect my laptop in the console port, the management came up.

I don't have this issue in the second one.

Any idea ?

Thanks in advance for your support.