Debugging SQLite R*tree - r

Question

I have an SQLite database containing an R*tree virtual table. This table is behaving rather oddly and I'm at a loss as to what is wrong. I would appreciate any pointers to aspects I could investigate!
> dbGetQuery(con, 'PRAGMA integrity_check')
integrity_check
1 ok
It seems fine...
> dbGetQuery(con, 'SELECT * FROM peakLoc LIMIT 5')
peakID scanStart scanEnd mzMin mzMax
1 18481 5540 5904 435.1880 435.2095
2 18429 5555 5644 408.7411 408.7459
3 18251 5621 5710 432.7190 432.7285
4 16415 6081 6173 432.2292 432.2470
5 16391 6089 6351 454.1823 454.1960
The general look of the R*tree table
> dbGetQuery(con, 'SELECT MIN(scanEnd), MAX(scanEnd) FROM peakLoc')
MIN(scanEnd) MAX(scanEnd)
1 51 19369
The bounds of scanEnd
> dbGetQuery(con, 'SELECT * FROM peakLoc WHERE scanEnd > 5000 LIMIT 5')
peakID scanStart scanEnd mzMin mzMax
1 20987 4839 6284 410.1729 410.2035
2 6705 9827 10132 738.8564 738.8674
3 15190 6482 6756 615.3235 615.3395
4 15189 6482 6756 509.2193 509.2258
5 12001 7449 7710 855.4534 855.4631
So far so good...
> dbGetQuery(con, 'SELECT * FROM peakLoc WHERE scanEnd > 6000 LIMIT 5')
[1] peakID scanStart scanEnd mzMin mzMax
<0 rows> (or 0-length row.names)
Where are the records?
The same is happening for the other columns with bigger-than once the comparator gets to an arbitrary large number. This behaviour is only present in the R*tree table - the regular tables works fine...
Have I stumbled upon a constraint in the R*tree module that I do not know about? All records in the R*tree comes from one big insert and I have not touched the underlying tables that the R*tree relies on...
edit:
On request from CL I've tried to create a reproducible example. At least on my system the following produces an R*tree with the same behaviour:
set.seed(1)
library(RSQLite)
con <- dbConnect(dbDriver('SQLite'), ':memory:')
dbGetQuery(con, 'CREATE VIRTUAL TABLE test USING rtree(id, xmin, xmax, ymin, ymax)')
x <- abs(rnorm(100))
y <- abs(rnorm(100))
data <- data.frame(id=1:100, xmin=x, xmax=x+2, ymin=y, ymax=y+3)
dbGetPreparedQuery(con, 'INSERT INTO test VALUES ($id, $xmin, $xmax, $ymin, $ymax)', bind.data=data)
dbGetQuery(con, 'SELECT max(xmax) FROM test')
dbGetQuery(con, 'SELECT * FROM test WHERE xmax > 4 LIMIT 5')
dbGetQuery(con, 'SELECT * FROM test WHERE +xmax > 4 LIMIT 5')
edit 2:
A database created with the commands given in the first edit can be downloaded from this link:
https://dl.dropboxusercontent.com/u/2323585/testdb.sqlite