Lightroom: inconsistent behavior when starting

Hi,
I've noted an inconsitent behavoir of LR when it is started in "non-standard" conditions. This is not critical, but upsetting as I get finally exactly the opposite of what I was expecting. (I've always encoutered this bug (since 2.6) on both vista & W7)

All my pictures and catalogs are on external disk:
for each "picture library" the files, the catalog & the technical data (preview, cache) are in a unique Windows directory on an eSata external drive with this approach:
- I can make full backup very easily
- I've a very safe confidentiality of the pictures (when the drive is off...)
- I can use my professional laptop for "personnal use"
And by the way the perf are very good with a 2Terabyte 7200RPM external disk (25 000 pictures of 19 & 50 MP).

The issue is that with this approach, I start from time to time LR without a library on-line and:
- LR asks me if I want start with the default lib or exit.
- I choose "exit"
- LR exits
- I connect my disk
- I relaunch LR
- and LR => starts automatically with the default lib (which is exactly the opposite of what I want).

I believe that:
- either LR should start in the default library at the first try
- or re-ask at the second
but not alone at the second start what I've refused at the first.

It is not a severe but, but it's irritating.