I recently purchase a vodafone prepay vodem K3772-Z.   It came with software v10.2.304 on it.  I installed it on my work laptop  - a dell latitude e6420 (< 8 months old) with Win7 32bit + all recent patches (pushed via company wsus).

Anyway everything works for about 20mins or so - connected to company vpn (juniper vpn client).  After 20 mins or so, the connection seems to stop working, firefox can't browse, vpn isn't connected.

Another 10mins and windows blue screens with a message about power driver error state (forgot exact msg).  The vodem stick is also quite warm.

I swapped the device at the vodafone store. Same issue with new device.  Has happened 5 or more times now.

I uninstalled the software and installed v10.2.302 from http://www.business.vodafone.com/site/bus/public/enuk/support/10_productsupport/laptop_connectivity/40_software/software/10_latest/p_software.jsp.

Still get same issue after 20-30mins.

Any ideas?  I saw another forum item suggested using https://www.vodafone.co.nz/mobile-broadband/help-and-support/index.jsp.