default extensions not being added when using "save as"

[#1]

Hi all
Not my area of expertise so am asking here.
Example of problem/annoyance ... open new Excel spreadsheet ... type data to it ... save the file using a file name .... the default extension .xls is added to the name automatically on saving. Just as it should.
However, if I reopen the same workbook ... click on file, "save as" ... delete the file name & extension .... change the file name ... the default extension is not added ... the computer demands I enter ".xls" manually.
Anyone think of why this annoyance should happen and how to fix it?
Thanks for any suggestions.

OJ

[#2]

Check under the filename box, where it says 'Save file as...' - if this is set to a specific file type the extension should be added. If it's set to 'All files' then it won't.
I think this is the case, at least.
Hope this helps,

[#3]

Just a thought, but when you see files on your desktop etc, are they displayed with the extension visible? If so, then try opening a Windows Explorer window, go to Tools -> Folder Options, and click the View tab. In this pane, tick the "Hide extensions for known file types" option and apply the changes. Try what you were doing before and see if that makes a difference. If not you can just change the setting back to what you had before. It's a long shot, but it's a shot
Otherwise I'm sure what orbrey says is correct.

[#4]

Thanks for the quick replies. It's all working fine now. My wife did shut down and reboot before I had a chance to look at the problem again so maybe it was a system glitch? Who knows? One of those things, I guess.
Thanks again.

OJ