[imp] incorrect display format

[Ahmed]

With the last couple of CVS updates I've begun to notice when a mailbox or 
horde summary refresh happens the display sometimes will:

a) not have the correct background colour (light blue in our case)
b) the text is the wrong size

seems to be intermittant and connected with the new-mail pop-up.
This goes away if we reload the page manually.
nothing unusual is reported in any of the logs.

PS: client tried: IE 5.50.4807.2300

System: RH7.1, apache 1.3.22 (stock redhat), HORDE/IMP latest CVS (15.5.02 8:00 
GMT)

any pointers?
Ahmed...