Ubuntu randomly locks up solid while mounting a network Windows share

[ubnewbie2]

I have been trying out 12.04 for a few days and I love it.

However, I had a few Windows shares on my network that I wanted to mount regularly, and while setting them up, I have had Ubuntu lock up solid twice. Nothing but a power cycle would get it going again.

It happened once when mounting one share manually from the command line, and again just now after I added a new share to fstab and issued mount -a from the command line.

Both shares are on an external drive attached to my adsl router which exposes them to the network as Windows shares.

[ubnewbie2]

and it just did it again as it booted, maybe because I now have those shares being mounted in fstab?

[ubnewbie2]

Can no-one help with this instability? I have had to put noauto on the lines in fstab where three Windows shares are being mounted, just to be able to boot reliably into Ubuntu

I just had it crash while umounting a share, and it went to a black screen with some sort of dump on it (and again needed to be powered off/on to get it going)

Is there a different type of underlying software (whatever it is) that I can use instead? For example, I am thinking of using smbnetfs, as that seems like it might be safer (using fuse - a userspace system).