more on shared folders not remapped

[casperton e2003]

Host W7Enterprise; VB 4.3.28
Guest W7Ultimate; GA 4.3.28

Shared folders mapped are not retained throuout reboots of guest.
They appear with big red cross in explorer; message that network mapping failed; vboxsvr subfolders do not appear in network view.

Workaround
admin level cmd with net use L: \\Vboxsvr\share then net use L: /del
Now is possible to disconnet mapped drives and add mapped drives. Network view shows shared folders.

Reinstalling GA 4.3.20 solves this issue.

Is it my guest installation or GA issue?

Thanks,
CTone

[noteirak]

Please read Minimum information needed for assistance and provide as zipped attachments the VM log file and the guest settings.