DELL 6224P constantly to restart

the 6224P constantly to restart like this:

Boot Menu 3.3.12.1
Select an option. If no selection in 10 seconds then
operational code will start.

1 - Start operational code.
2 - Start Boot Menu.
Select (1, 2):

Operational Code Date: Fri Nov  7 10:36:26 2014
Uncompressing.....

There was an error during decompression... resetting the switch

 

select 2 i can get in BOOT MENU，and functions in the boot menu are OK，for example i can Load new operational code using XMODEM,Reset the system,Restore to factory defaults and so on... and i have flashed the latest rom by XMODEM,but the problem still exists.

if shutdown the 6224P for a day or more ,it will get OK for some minutes.

Here are some messages before it constantly to restart  :

<187> JUN 13 18:26:34 192.168.70.132-1 LLDP[213756864]: lldp_util.c(2471) 309 %%
 lldpTimerProcess(): LLDPDU Transmit Failed! Unable to reserve network buffer fo
r transmission


<187> JUN 13 18:27:04 192.168.70.132-1 LLDP[213756864]: lldp_util.c(2471) 310 %%
 lldpTimerProcess(): LLDPDU Transmit Failed! Unable to reserve network buffer fo
r transmission


<187> JUN 13 18:27:34 192.168.70.132-1 LLDP[213756864]: lldp_util.c(2471) 311 %%
 lldpTimerProcess(): LLDPDU Transmit Failed! Unable to reserve network buffer fo
r transmission


<187> JUN 13 18:28:04 192.168.70.132-1 LLDP[213756864]: lldp_util.c(2471) 312 %%
 lldpTimerProcess(): LLDPDU Transmit Failed! Unable to reserve network buffer fo
r transmission
<187> JUN 13 18:30:30 192.168.70.132-1 LLDP[213756896]: lldp_util.c(2471) 326 %%
 lldpTimerProcess(): LLDPDU Transmit Failed! Unable to reserve network buffer fo
r transmission


<187> JUN 13 18:31:00 192.168.70.132-1 LLDP[213756896]: lldp_util.c(2471) 327 %%
 lldpTimerProcess(): LLDPDU Transmit Failed! Unable to reserve network buffer fo
r transmission

Exception: taskID = e6109b0, vectNum = 700, pEsf = 0xe611b88
saving crash record in crashdump.1

  NAME         ENTRY       TID    PRI   STATUS      PC       SP     ERRNO  DELAY

----------  ------------ -------- --- ---------- -------- -------- ------- -----

poe_monito  Error 1 decompressing devshell symbols while refilling
hpcPwrdsineP  e6109b0 255 READY      0x82ffa4  e6106f0       0     0

stack: base 0xe6109b0  end 0xe6089b0 size 32768  high 1264  margin 31504
options: 0x1009001

vector: 0x700



Stack Trace:

<187> JUN 13 18:31:30 192.168.70.132-1 LLDP[213756896]: lldp_util.c(2471) 330 %%
 lldpTimerProcess(): LLDPDU Transmit Failed! Unable to reserve network buffer fo
r transmission

0x82ffa4: poe_device_read (0x82fcec) + 0x2b8
0x830374: poe_device_read (0x82fcec) + 0x688
0x7651740 (dot1s_timer_task): task 0x7651740 has had a failure and has been stop
ped.
0x7651740 (dot1s_timer_task): fatal kernel task-level exception!

<187> JUN 13 18:32:00 192.168.70.132-1 LLDP[213756896]: lldp_util.c(2471) 331 %%
 lldpTimerProcess(): LLDPDU Transmit Failed! Unable to reserve network buffer fo
r transmission

0x831e80: hpcPwrdsinePoeMsgChannelPrioritySet (0x8318d8) + 0x5a8
0x836eac: hpcPwrdsinePoeChannelToPhysicalPortMap (0x833d3c) + 0x3170
0xd8bbe10 (isdpTask): task 0xd8bbe10 has had a failure and has been stopped.
0xd8bbe10 (isdpTask): fatal kernel task-level exception!
0x1dbcd20: vxTaskEntry (0x1dbccc4) + 0x5c
r0     =        0   sp     =  e6106f0   r02    =        0   r03    =  e610820

r04    =       45   r05    =        0   r06    =       64   r07    =      3e8

r08    =        0   r09    =  e610820   r10    =  e610821   r11    =       35

r12    =   989680   r13    =        0   r14    =        0   r15    =        0

r16    =        0   r17    =        0   r18    =        0   r19    =        0

r20    =        0   r21    =        0   r22    =        0   r23    =        0

r24    =        0   r25    =        0   r26    =        0   r27    =  e610904

r28    =  e610903   r29    =  e6108c0   r30    =   836c9c   r31    =  e6106f0

msr    =  2029200   lr     =   830400   ctr    =  1e6a91c   pc     =   82ffa4
cr     = 40000048   xer    =        0