drv <- dbDriver("PostgreSQL")
con <- dbConnect(drv, dbname="dbname",host="host",port=5432,user="usr",password="pwd")

vSQLDF <- sqldf(vSQL, connection=con)

Error in dbPreExists && !overwrite : invalid 'x' type in 'x && y'

> sessionInfo()
R version 2.15.2 (2012-10-26)
Platform: x86_64-pc-linux-gnu (64-bit)

locale:
 [1] LC_CTYPE=cs_CZ.UTF-8       LC_NUMERIC=C               LC_TIME=en_GB.UTF-8        LC_COLLATE=cs_CZ.UTF-8     LC_MONETARY=en_GB.UTF-8
 [6] LC_MESSAGES=en_US.UTF-8    LC_PAPER=C                 LC_NAME=C                  LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_GB.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] tcltk     stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
 [1] lattice_0.20-13       sqldf_0.4-6.4         RSQLite.extfuns_0.0.1 RSQLite_0.11.2        chron_2.3-43          gsubfn_0.6-5
 [7] proto_0.3-10          RPostgreSQL_0.3-3     DBI_0.2-5

loaded via a namespace (and not attached):
[1] grid_2.15.2  tools_2.15.2

PostgreSQL 9.1.9 on x86_64-unknown-linux-gnu, compiled by gcc-4.4.real (Debian 4.4.5-8) 4.4.5, 64-bit

if (request.con) dbPreExists <- attr(connection, "dbPreExists")

dbPreExists <- attr(connection, "dbPreExists") #see error gets thrown.

debug(sqldf)  # then repeat operation