Not sure it will solve the problem you are having but I can see 2 area's of improvement.
Firstly, you don't have to do Reader.Close as it is not used as this are all non-select queries. Actually, Reader.Close might cause an error if it wasn't opened before, come to think of it.
Secondly, instead of adding all the variables in the SQL I would use AddParameter and SetParameter, which might be faster (but not much if you don't run it in a loop) and will avoid the hassle of dealing with the single quotes.
RBS