[continued from bug found in Lite version.]
I cleared out x2 pro reg keys on computer "A" and:
installed Pro v1.7.2.6 on "A" (date change on "B" success)
and then updated it to v1.8.0.1 (date change on "B" failure)
and kept rolling back in steps to v1.7.2.16[DBG] (all have date change on "B" failure)
and then reinstalled v1.7.2.6 as a final check (date change on "B" success)
______________________________________________________________________
scorecard:
* x2Pro v 1.8.0.11 on "A" cannot change folder dates on "B"

* x2Pro v 1.7.2.6 on "A" can change folder dates on "B"

* x2Pro v 1.8.0.1 on "A" cannot change folder dates on "B"

* x2Pro v 1.7.2.22 on "A" cannot change folder dates on "B"

* x2Pro v 1.7.2.19beta on "A" cannot change folder dates on "B"

* x2Pro v 1.7.2.16[DBG] on "A" cannot change folder dates on "B"

* re-check: x2Pro v 1.7.2.6 on "A" still can change folder dates on "B"

* x2Pro v 1.8.0.11 on "A" still cannot change folder dates on "B"

Except for the v1.8.0.11 reports, I used NO customization in the tests, using default settings as freshly installed.
for reference: both machines are running 32-bit XP/sp3.
"A" runs XP-pro; "B" runs XP-media center edition.
both machines are current with all MS critical updates.
AV on both machines is MS Security Essentials