10.5.3 spaces/dock problem

Well now.

Newly upgraded to 10.5.3 on a Mac Pro 4-core.

I observe that if I try to switch spaces with CTRL-arrow too quickly, I
get these messages in the console log:

29/05/08 13:41:53 com.apple.launchd[141]
([0x0-0x31031].com.apple.dock[772]) Exited abnormally: Segmentation
fault
29/05/08 13:41:53 [0x0-0x32032].com.apple.dock[774] WorkspacesActivate:
read out an invalid workspace (0x10002!
29/05/08 13:41:54 Dock[774] Could not create a directory for
<DOCKFolderTile: 0x81b800> error = Error Domain=NSOSStatusErrorDomain
Code=-35 "Operation could not be completed. (OSStatus error -35.)" (no
such volume)
29/05/08 13:41:54 Dock[774] Could not create a directory for
<DOCKFolderTile: 0x823800> error = Error Domain=NSOSStatusErrorDomain
Code=-35 "Operation could not be completed. (OSStatus error -35.)" (no
such volume)

Anyone else seen this?