Invalid hostid on SERVER line

We are running SolidNetWork License Administrator on WindowsServer 2003 SP2. Every few weeks we get the error message below.The clients cant find the license server. After i do a reread ofthe license file it works fine for another few weeks.

12:15:16 (SW_D) Wrong hostid on SERVER line for license file:
12:15:16 (SW_D) E:\SolidWorks\LICMAN\licenses\sw_d.lic
12:15:17 (SW_D) SERVER line says FLEXID=9-*******, hostid is (Can'tget hostid of type 15 [Cannot read dongle: check dongle or driver.(-110,499)])
12:15:17 (SW_D) Invalid hostid on SERVER line
12:15:17 (SW_D) Disabling 45 licenses from featurecae_cosmosfloworkspe(0014 63DC 8014 6890 )
12:15:17 (SW_D) Disabling 45 licenses from featurecae_cwadvpro(0079 1969 F233 7AC0 )
12:15:17 (SW_D) Disabling 135 licenses from feature dwgeditor(00C9FBE2 618B 958C )
12:15:17 (SW_D) Disabling 45 licenses from feature solidworks(00A0843E 054E 621B )
12:15:17 (SW_D) Disabling 45 licenses from featureswofficepremium(0084 3C79 63AB 5C6A )
12:17:17 (SW_D) No valid hostids, exiting
12:17:17 (SW_D) EXITING DUE TO SIGNAL 25 Exit reason 2
12:17:22 (lmgrd) SW_D exited with status 25 (Invalid host)
12:17:22 (lmgrd) Please correct problem and restart daemons
14:10:09 (lmgrd) TIMESTAMP 10/4/2008
20:10:12 (lmgrd) TIMESTAMP 10/4/2008
2:10:14 (lmgrd) TIMESTAMP 10/5/2008
8:10:17 (lmgrd) TIMESTAMP 10/5/2008
14:10:20 (lmgrd) TIMESTAMP 10/5/2008
20:10:20 (lmgrd) TIMESTAMP 10/5/2008
2:10:24 (lmgrd) TIMESTAMP 10/6/2008
8:10:28 (lmgrd) TIMESTAMP 10/6/2008
13:08:49 (lmgrd) Rereading license file... Requested fromadministrator@insideapp
13:08:49 (lmgrd) Starting vendor daemon at port 25735
13:08:49 (lmgrd) Using vendor daemon port 25735 specified inlicense file
13:08:50 (lmgrd) Reread: Started SW_D (pid 2B628)13:08:50 (lmgrd)Done rereading
13:08:50 (lmgrd) ...Finished rereadingSolidworksEdrawings