[plt-scheme] namespace mismatch and PLaneT

Hello!

I wanted to contribute a package to PLaneT (package name = "sedna"), and 
observed the following features:
  1. The .plt file successfully compiles with setup-plt for any PLT version 
(tested for at least v 360, 399.0.9 and 399.0.17)
  2. When uploaded to PLaneT, the package can be require'd from PLaneT 
without errors for PLT version<399 (tested for at least v 352 and 360)
  3. When require'd from PLaneT from PLT v 399.0.9, a "namespace mismatch" 
error message (fully given below) is displayed for the first time, but not 
for subsequent times (IIUC, the package fails to compile, and a non-compiled 
version is then used).
  4. When require'd from PLaneT from PLT v 399.0.17, the error message 
occurs both for the first time and for subsequent ones.

The message:

require: namespace mismatch; reference (phase 1) to a module "C:\Program 
Files\PLT-3.99.0.17\collects\scheme\private\kw.ss" that is not available 
(phase 0) in: #%app

The file mentioned in the error message exists.

How can I locate a problem in a package in a more detail? Is there an 
installation log file or anything that displays a module/line for an 
erroneous code? The package seems not using any PLT-399-specific features.

Any advice would be very helpful

Dmitry