AdHoc Networks...

[hrios]

Will an AdHoc Network pose any interference problems in the vicinity of an infrastructure network?

[amitubale]

Yes,There will be radio interference if Ad-Hoc APs are on the same radio frequency channels used by the APs on the infrastucture mode.

Conduct a site survey and config each device on a non-overlapping channel to avoide interference.

[lbarisdale]

If both networks are on the same channels then yes. You should spread out the channels by putting infra on 11 and adoc on 1. If you have another network then put it on 5 or 6.