delete vlan

Switch#dir
Switch#delete flash:/vlan.dat
Switch#reload

try to change 2950 to vtp mode transparent, write configuration and repeat your tasks

Normally it has to work when you delete vlan.dat and reload it.

I had the same issue and got it working by changing the vtp mode to server, then deleting the vlan.dat file and reloading the switch.  Once it came back up I changed the mode back to transparent and all was well.  Please keep in mind that I did this with the switch on my desk because changing the vtp mode to server while on the network could have dire consequences if on the network.  Cheers!