Anyone had problems with a recone job?

I've got an old JBL B380 sub. Not my preferred sub, but what can I say, it was cheap.

The 2235 15" driver had foam rot. I took it to the local JBL dealer to have it reconed. After the recone, it just doesn't seem to handle the power like it use to. Seems to bottom-out quite easily.

Does this mean it wasn't hung properly or are there other mistakes that could have been made?

I'm driving it with a 500 watt Sunfire sub-amp.

Any thoughts would be appreciated.
It will have to break in again just like when it was new.
It probably wasn't reconed but just a new surround for the cones. I had this surround disintegration happen to my JBL L112's and had new surrounds put on and I never did like the bass again after that. Perhaps, it was a matter of "break in" but they were in a secondary system and I ended up selling them before I put many more hours on them. I have heard that the surrounds do need break in so maybe it will be ok.