numbers in cell are arabic and romans

Hello, 

My colleagues from accountant department uses excel with tons of number. 
2 of them came to me with a problem, where numbers in cell was part arabic and part roman (ex. XI.22, 41.IV)
Can anyone have some idea what could cause this? Saddly I dont watch their hands so im not sure what kind of steps was done before this happend. My personal suspicion is on "dot". In the source excel were numbers like this ex. 122.33, could that "dot" cause the problem?