I have a 2950 switch. I start with the default Startup file (no configuration), I play with the equipment creating some vlans and when I turn off and on the switch (not saving the running-confi file)... the configuration is erased and start with default again but vlans still exist.... is it OK that vlans are not erase in this switches after a reload?. Manually with the "no vlan x" there is no problem.
It's perfectly normal. The startup config is separate from the vlan database. The vlans are stored in this file, and yes, it's on every switch I've seen. (2950, 3750, 4500 series)