[Lazarus] Why does Lazarus insist on rebuilding the LCL?

[Bart]

Every time I update Lazarus, I rebuild it from commandline:

make clean all OPT='-gl'

Then when I open the start Lazarus and want to build the last project
I was working on, it immediately rebuilds the enitre LCL
(I thought I had just done so by using make clean all)

Free Pascal Compiler version 2.4.2 [2010/11/08] for i386
Copyright (c) 1993-2010 by Florian Klaempfl
Target OS: Linux for i386
...
"Compiling package LCLBase 1.0.1" completed
...
Compiling lcl.pas
...
"Compiling package LCL 1.0.1" completed
Options changed, recompiling clean with -B
Hint: Start of reading config file /etc/fpc.cfg
Hint: End of reading config file /etc/fpc.cfg
Free Pascal Compiler version 2.4.2 [2010/11/08] for i386
Copyright (c) 1993-2010 by Florian Klaempfl
Target OS: Linux for i386
Compiling maskedittest.lpr
...
Linking maskedittest
457 lines compiled, 11.0 sec
3 warning(s) issued
21 hint(s) issued
5 note(s) issued
Project "maskedittest" successfully built

On numerous occasions Lazarus tends to repeat this process of
rebuilding LCL base, even when I did not update and did not change any
file of the LCL myself.

Why does Lazarus do this.
It seems unnecessary to me and it's driving me insane.
(Rebuilding LCL takes > 1,5 min. on my ancient system)

Bart