Querying large database using read.odbc.ffdf exhausts memory in R - r

Question

I'm trying to query a large database and then save the returned result as an ff object using the read.odbc.ffdf function. The following code should allow me to pull in a thousand rows at a time, save the data as an ff object, and then move onto the next thousand rows, appending these to the previous file, so that I can preserve memory:
library(ff);
library(ffbase);
library(ETLUtils);
library(RODBC);
sqlcode <- "SELECT f.*
FROM table1 AS f;";
data <-read.odbc.ffdf(query = sqlcode,
odbcConnect.arg = list('data1; db=research'),
nrows = 1000,
next.rows = 1000,
BATCHBYTES = 100000;
dim(data);
However, when I do this, R eventually eats up all my RAM, and eventually the process terminates before the object "data" is completely filled. Inspecting "data" reveals the following error message:
read.odbc.ffdf 1.. () odbc-read=822.06secError in if (nrow(dat) == 0) { : argument is of length zero
Any ideas what this error message means? How can I query this database without exhausting my memory (4 GB RAM)? I expect the option "BATCHBYTES" in combination with "first.rows" and "next.rows" to keep my memory usage low (within 100,000 bytes, which should be enough for my system).
Am I just not understanding how function read.odbc.ffdf works with the first.rows, next.rows, and BATCHBYTES options?