The "Configure auto correct/abbreviation" dialog allows "error/abbreviation" entries to contain spaces, but the editor does not respond to auto complete when using an autocomplete entry with spaces.
1. Create a new autocomplete entry. Set is to replace "W R" with "WHERE".
2. Apply the change.
3. (With auto-complete enabled), go to an editor and type "W R" (without the quotes), and press spacebar. "W R" will not be replaced with "WHERE".
This has been confirmed on Windows XP machines with SQuirreL 2.5.1 and SQuirreL 2.6.1.