Calc re-arranging formulas (possibly spell checking??) PLEASE HELP

Recurrent frustrating problem (LO 3, 4, & now 5 series on Win XP & now 8.1). As an example, sheet4 (named “Totals”) is used to consolidate data on sheets 1-3 (named “Tom”, “Dick” & “Harry”). In (let’s say) cell B1 on sheet 4 I’ll try to enter a formula (hitting the = sign or clicking on the = icon to the left of the formula bar, doesn’t seem to make a difference) and using the mouse to navigate to and select the cells on sheets 1-3, hitting + to go to the next cell, hitting enter when done.
The formula bar as I’m selecting the cells will read something like
“=Tom.b1+Tom.b3+Dick.b1+Dick.b3+Harry.b1+Harry.b3”,
but when I hit enter sheet4 B1 reports “#NAME?” and the formula is rearranged to something like “Dick.b1Tom.b1+Tom.b3++Dick.b3+Harry.b1+Harry.b3” (concatenating some cell names so they don’t make sense, with a double ++ in the middle of the formula).
This happens maybe 10% of the time. I’ve learned to live with it and edit the formula when the error occurs, but I’d really like to know what the problem (and fix) is.

Additional info: Data type (“format cells”) was undefined (defaults to general?) as I wasn’t ready to enter data yet. Formatting all the cells (number, comma, 2 decimal places) prior to setting up the formulas MAY have fixed the problem (but as it seemingly only occurred 10% of the time I don’t know if it’s truly fixed). Could an inappropriate data type account for what I was seeing?

I can’t reproduce the issue, even copying your formula from here, with cell language either English or Spanish.
You can try deactivating all autocorrect options Menu/Tools/Autocorrect.
If it doesn’t work, please try resetting the user profile, sometimes solves strange issues.
https://wiki.documentfoundation.org/UserProfile,