Steps to reproduce:
1 - Open the attached patch
Note the size of the radio and toggle. Note also they have "send" symbols set to "xxx" and "yyy" respectively
2 - Click on the big bang at the top
This composes a symbol containing space characters and sends it as a label to both the radio and the toggle.
This seems to work: the label is actually set with spaces, and the radio and toggle still work.
However, if you right-click on any of them and try to select "properties", the properties dialog won't open
3 - Now save the patch and close it
4 - Open the patch again. The radio and toggle properties have been completely "reset": their size have been reset to default, and also the "number" property of the radio. They have lost their "send" symbol too: you can see the outlet and if you use them, the "r" objects won't receive anything.
However, if you open the properties dialog of the radio or toggle, you'll see that the "send" property is still there (not the same can be said for the size and number); if you now do Apply or Ok, the send symbol will be restored.
So, spaces in the label of a gui object cause weirdnesses and potential disaster. Note that data is lost (the properties of the gui objects) if the patch is saved after assigning such a label, and i is lost silently with no error message at any moment.
There are ather "forbidden" characters ithat don't behave properly n labels, such as the open square bracket "[" (as reported in another bug report). However the space character is more disatrous as it causes data loss.
Object should either accept ALL characters for a label, or properly detect and refuse forbidden characters, which should be documented, avoiding unexpected consequences.