Post Discretionary question.

I had a 401k through my employer a few years ago, they matched up to 3%. i took advantage of that and put in what i needed to get the matching money. anways, i quit and took it all out and everything was find and dandy. well 2 years later i went back to work for them and signed up for the 401k again. when i looked at my 1st statement there was over 3000 in it. the weird thing was i only put in maybe 100 bucks so far. i called the investement firm and they said it was my money and nothing was wrong. well now, im seeing contributions into my account with this as the source "Post 06 ER Discretionary". i have no idea what this is and want to find out. also want to know if there is something glitch still putting money in my account for no reason. thanks.