Yes, i heard the same from some people, if there is change in salaries, they may reject and the application process also takes time.
If your salary is more than the previous months, it is okay, As long as they are more than 10,000...
If first 3months is 11,000 and next 2months is 8000 and last month as 9000. it can be a problem.
If it is 11000 for first 2months and 11000 above for next few months, no problem - as it is more than the minimum 10k..